Human iNKT cell activation using glycolipids with altered glycosyl groups

ABSTRACT

Glycosphingolipids (GSLs) bearing α-glucose (α-Glc) that preferentially stimulate human invariant NKT (iNKT) cells are provided. GSLs with α-glucose (α-Glc) that exhibit stronger induction in humans (but weaker in mice) of cytokines and chemokines and expansion and/or activation of immune cells than those with α-galactose (α-Gal) are disclosed. GSLs bearing α-glucose (α-Glc) and derivatives of α-Glc with F at the 4 and/or 6 positions are provided. Methods for iNKT-independent induction of chemokines by the GSL with α-Glc and derivatives thereof are disclosed. Methods for immune stimulation in humans using GSLs with α-Glc and derivatives thereof are provided.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No. 15/689,165, filed Aug. 30, 2017, which is a divisional of U.S. patent application Ser. No. 14/480,521, filed on Sep. 8, 2014, which claims priority to U.S. Provisional Patent Application No. 61/874,946, entitled HUMAN iNKT CELL ACTIVATION USING GLYCOLIPIDS WITH ALTERED GLYCOSYL GROUPS, filed on Sep. 6, 2013, the contents of which are hereby incorporated by reference as if set forth in their entirety.

FIELD OF THE INVENTION

This invention relates generally to the field of immune therapeutics. In particular, the instant disclosure relates to glycolipids and variants thereof that modulate invariant natural killer T (iNKT) cells in humans and stimulate cytokine and/or chemokine production and thus transactivate downstream immune cells thereby bridging the innate and adaptive immunity.

BACKGROUND OF THE INVENTION

Natural killer-like T (NKT) cells are a distinct population of T lymphocytes with enormous therapeutic potential in the treatment of diseases such as cancer and autoimmune disorders. Invariant natural killer T (iNKT) cells form a subset of regulatory T cells with features of both innate and adaptive immunity. In contrast to conventional T cells that are activated by a peptide presented by an MHC class I or II molecule, iNKT cells recognize lipid derivatives present in the context of CD1d, a non-classical MHC I molecule expressed on antigen presenting cells (APCs).

α-GalCer (α-galactosylceramide), a glycolipid composed of a-linked galactose, sphingosine, and an acyl tail, was obtained by structural optimization of agelasphin, which is isolated from the marine sponge Agelas mauritianus. It has been found to exhibit antitumor activity both in vitro and in vivo and shown to be the most potent ligand yet known for both mouse and human invariant natural killer T cells (iNKT cells).

Invariant NKT cells (iNKT cells) carry the invariant TCR-α chain (Vα14/Jα18 in mice and Vα24/Jα18 in humans) and co-express CD161 antigen (NK cell marker NK1.1 in mice and NKR-P1A in humans). (1) Lantz, O.; Bendelac, A. J. Exp. Med. 1994, 180, 1097; (2) Dellabona, P.; Padovan, E.; Casorati, G.; Brockhaus, M.; Lanzavecchia, A. J. Exp. Med. 1994, 180, 1171; (3) Makino, Y.; Kanno, R.; Ito, T.; Higashino, K.; Taniguchi, M. Int. Immunol. 1995, 7, 1157; and (4) Davodeau, F.; Peyrat, M. A.; Necker, A.; Dominici, R.; Blanchard, F.; Leget, C.; Gaschet, J.; Costa, P.; Jacques, Y.; Godard, A.; Vie, H.; Poggi, A.; Romagne, F.; Bonneville, M. J. Immunol. 1997, 158, 5603. They secrete large amounts of Th1 (e.g., IFN-γ, IL-2) and Th2 (e.g., IL-4, IL-6) cytokines in response to αGalCer presented by the CD1d molecule on the antigen-presenting cells.⁵⁻⁹ (5) Kawano, T.; Cui, J.; Koezuka, Y.; Toura, I.; Kaneko, Y.; Motoki, K.; Ueno, H.; Nakagawa, R.; Sato, H.; Kondo, E.; Koseki, H.; Taniguchi, M. Science 1997, 278, 1626; (6) Yoshimoto, T.; Paul, W. E. J. Exp. Med. 1994, 179, 1285; (7) Arase, H.; Arase, N.; Nakagawa, K.; Good, R. A.; Onoe, K. Eur. J. Immunol. 1993, 23, 307; (8) Kawakami, K.; Yamamoto, N.; Kinjo, Y.; Miyagi, K.; Nakasone, C.; Uezu, K.; Kinjo, T.; Nakayama, T.; Taniguchi, M.; Saito, A. Eur. J. Immunol. 2003, 33, 3322; and (9) Nieuwenhuis, E. E.; Matsumoto, T.; Exley, M.; Schleipman, R. A.; Glickman, J.; Bailey, D. T.; Corazza, N.; Colgan, S. P.; Onderdonk, A. B.; Blumberg, R. S. Nat. Med. 2002, 8, 588. These secreted cytokines could then transactivate downstream immune cells, including dendritic cells (DC), natural killer cells (NK), B cells, CD4⁺ T and CD8⁺ T cells, and thereby bridging the innate and adaptive immunity.¹⁰⁻¹² (10) Eberl, G.; MacDonald, H. R. Eur. J. Immunol. 2000, 30, 985; (11) Eberl, G.; Brawand, P.; MacDonald, H. R. J. Immunol. 2000, 165, 4305; and (12) Kitamura, H.; Ohta, A.; Sekimoto, M.; Sato, M.; Iwakabe, K.; Nakui, M.; Yahata, T.; Meng, H.; Koda, T.; Nishimura, S.; Kawano, T.; Taniguchi, M.; Nishimura, T. Cell. Immunol. 2000, 199, 37.

However, the counterbalance of Th1 and Th2 cytokines may limit the clinical application of αGalCer for the treatment of a variety of disorders.¹³⁻¹⁶ (13) Tahir, S. M.; Cheng, O.; Shaulov, A.; Koezuka, Y.; Bubley, G. J.; Wilson, S. B.; Balk, S. P.; Exley, M. A. J. Immunol. 2001, 167, 4046; (14) Dhodapkar, M. V.; Geller, M. D.; Chang, D. H.; Shimizu, K.; Fujii, S.; Dhodapkar, K. M.; Krasovsky, J. J. Exp. Med. 2003, 197, 1667; (15) Giaccone, G.; Punt, C. J.; Ando, Y.; Ruijter, R.; Nishi, N.; Peters, M.; von Blomberg, B. M.; Scheper, R. J.; van der Vliet, H. J.; van den Eertwegh, A. J.; Roelvink, M.; Beijnen, J.; Zwierzina, H.; Pinedo, H. M. Clin. Cancer Res. 2002, 8, 3702; and (16) Bricard, G.; Cesson, V.; Devevre, E.; Bouzourene, H.; Barbey, C.; Rufer, N.; Im, J. S.; Alves, P. M.; Martinet, O.; Halkic, N.; Cerottini, J. C.; Romero, P.; Porcelli, S. A.; Macdonald, H. R.; Speiser, D. E. J. Immunol. 2009, 182, 5140.

SUMMARY OF THE INVENTION

Accordingly, many analogues were designed to stimulate selective Th1 or Th2 cytokine responses of iNKT cells. Glycolipids with marked Th1 bias in both mice and men, leading to superior tumour protection in vivo. For example, glycosphingolipids (GSLs) with the truncated sphingosine tail could drive immune responses into Th2 direction and prevented autoimmune encephalomyelitis.¹⁷ Miyamoto, K.; Miyake, S.; Yamamura, T. Nature 2001, 413, 531. On the other hand, GSL with phenyl ring on the acyl chain induced Th1-biased cytokines in mice and humans and displayed more potent anticancer activities against breast, lung and melanoma tumors in mice.^(18,19) (18) (Chang, Y. J.; Huang, J. R.; Tsai, Y. C.; Hung, J. T.; Wu, D.; Fujio, M.; Wong, C. H.; Yu, A. L. Proc. Natl. Acad. Sci. U.S.A 2007, 104, 10299 and (19) Wu, T. N.; Lin, K. H.; Chang, Y. J.; Huang, J. R.; Cheng, J. Y.; Yu, A. L.; Wong, C. H. Proc. Natl. Acad. Sci. U.S.A 2011, 108, 17275.

Examination of the binary interaction between CD1d and glycolipids, as well as the ternary interaction between iNKT TCR and CD1d-glycolipid complex elucidated the mechanisms underlying their structure-activity relationships (SAR). As compared to αGalCer, phenyl GSLs with the same glycosyl group exhibited stronger binary and ternary interactions, leading to more Th1-biased responses, and the biological responses had a significant correlation with the binding avidities of the ternary complex both in mice and humans. 19-21 (19) Wu, T. N.; Lin, K. H.; Chang, Y. J.; Huang, J. R.; Cheng, J. Y.; Yu, A. L.; Wong, C. H. Proc. Natl. Acad. Sci. U.S.A 2011, 108, 17275; (20) Liang, P. H.; Imamura, M.; Li, X.; Wu, D.; Fujio, M.; Guy, R. T.; Wu, B. C.; Tsuji, M.; Wong, C. H. J. Am. Chem. Soc. 2008, 130, 12348; and (21) Li, X.; Fujio, M.; Imamura, M.; Wu, D.; Vasan, S.; Wong, C. H.; Ho, D. D.; Tsuji, M. Proc. Natl. Acad. Sci. U.S.A 2010, 107, 13010.

Glycosphingolipids (GSLs) bearing α-galactosyl group (αGal) and phenyl ring on the acyl chain were found to be more potent than α-galactosyl ceramide (αGalCer) to stimulate invariant NKT (iNKT) cells. Their activities in mice and humans correlated well with the binding avidities of the ternary interaction between iNKT TCR and CD1d-GSL complex.

Invariant natural killer T (iNKT) cells are known to have marked immunomodulatory capacity due to their ability to produce copious amounts of effector cytokines. There is a need for improved glycosphingolipids that stimulate human invariant NKT (iNKT) cells and modulate cytokine and chemokine production in humans.

Accordingly, the present disclosure is based on the unexpected discovery that glycosphingolipids (GSLs) with α-glucose (α-Glc) exhibit stronger induction in humans (but weaker in mice) of cytokines and chemokines and expansion and/or activation of immune cells than those with α-galactose (α-Gal). The change of the 4′-OH direction on the glycosyl group led to different bioactivities in mice and humans. Alterations at the 6 position of the glycosyl group also showed variable effects on the biological responses. GSLs with α-Glc and derivatives of α-Glc with F at the 4 and/or 6 positions are disclosed herein. Methods for iNKT-independent induction of chemokines by the GSL with α-Glc and derivatives of α-Glc are disclosed. Methods for immune stimulation in humans using GSLs with α-Glc and derivatives of α-Glc thereof are provided.

The present disclosure provides a method for augmenting an immunogenicity of an antigen in a subject in need thereof, comprising combined administration said antigen as conadministration or coformulation with an adjuvant composition comprising a GSLs of the general Formula 1.

According to the present invention, the use of GSLs as an immune adjuvant results in an enhancement and/or extension of the duration of the protective immunity induced by the antigen and is attributed at least in part to the enhancement and/or extension of antigen specific Th1-type responses.

The GSLs-a-Glc-containing adjuvant of the invention can be conjointly administered with any antigen, in particular, with antigens derived from infectious agents or tumors. Preferably, the adjuvant and antigen are administered simultaneously, most preferably in a single dosage form.

In a further embodiment, the invention provides a prophylactic and/or therapeutic method for treating a disease in a subject comprising administering to said subject an immunoprotective antigen together with an adjuvant composition that includes GSLs. As specified herein, this method can be useful for preventing and/or treating various infectious or neoplastic diseases.

In conjunction with the methods of the present invention, also provided are pharmaceutical and vaccine compositions comprising an immunogenically effective amount of an antigen and an immunogenically effective amount of an adjuvant selected from GSLs within Formula 1 as well as, optionally, a pharmaceutically acceptable carrier or excipient.

Accordingly, in one aspect, the present disclosure relates to structural and functional exemplars of immune adjuvant compounds of Formula (I):

or pharmaceutically acceptable salt thereof; wherein R¹, R², R³, R⁴, R⁵, n and m are as described herein.

In some embodiments, R⁴ is of Formula (II):

wherein i and R⁶ are as described herein.

In some embodiments, R⁴ is of Formula (III):

wherein j, k, R⁷ and R⁸ are as described herein.

Aspects of the disclosure also relates to pharmaceutical compositions comprising (i) a compound disclosed herein in an amount sufficient to stimulate an immune response in when administered to a subjects, including humans, and (ii) a pharmaceutically acceptable excipient.

In some embodiments, the pharmaceutical composition comprises an antigen and a vaccine adjuvant. In certain embodiments, the antigen is a tumor antigen.

In some embodiments, the pharmaceutical composition comprises an anti-cancer therapeutic.

In some embodiments of the pharmaceutical composition, R⁴ in the compound is selected from substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl, and wherein the compound is capable of increasing Th1 cytokines in humans with minimum accompanying increase in Th2 cytokines.

Aspects of the invention relates to methods for stimulating an immune response in a human subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of a composition disclosed herein.

In some aspects, the compound is administered in amount capable of elevating invariant Natural Killer T (iNKT) cells in humans.

In some aspects, administration of the compound increases cytokine and/or chemokine production in humans. In some embodiments, the cytokine production is sufficient to transactivate downstream immune cells. In some embodiments, the downstream immune cells comprise one or more of dendritic cells (DC), natural killer cells (NK), B cells, CD4⁺ T and CD8⁺ T cells.

In some aspects, the cytokines comprise Th1 cytokines. In some embodiments, the Th1 cytokines are selected from: interferon-gamma (IFN-γ), GM-CSF, TNFα, interleukin 2, interleukin 12 and interleukin 10.

In some aspects, the chemokines are selected from: RANTES, MIP-1α, KC, MCP-1, IP-10 and MIG.

In some aspects, administration of the composition has an anti-cancer effect. In some embodiments, the cancer is selected from the group consisting of lung cancer, breast cancer, hepatoma, leukemia, solid tumor and carcinoma.

In some embodiments, R⁴ in the compound is selected from substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl, and wherein increase in Th1 cytokines in humans exceeds any increase in Th2 cytokines.

Aspects of the invention relates to methods for elevating invariant Natural Killer T (iNKT) cells production in a human subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of a composition, wherein the composition comprises a compound disclosed herein. In some embodiments, the elevation of iNKT levels is greater when compared to the elevation resulting from administration of an equivalent amount of a glycolipid analogue comprising alpha-galactose (αGal) as the glycosyl head group.

Aspects of the invention relates to methods for stimulating cytokine and/or chemokine production in a human subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of a composition, wherein the composition comprises an amount sufficient to increase cytokine/chemokine production, of a compound disclosed herein.

In some aspects, cytokine production is sufficient to transactivate downstream immune cells. In some embodiments, the downstream immune cells comprise one or more of dendritic cells (DC), natural killer cells (NK), B cells, CD4⁺ T and CD8⁺ T cells.

In some aspects, the cytokines comprise Th1 cytokines. In some embodiments, the cytokines are selected from: interferon-gamma (IFN-γ), GM-CSF, TNFα, interleukin 2, interleukin 12 and interleukin 10.

In some aspects, the chemokines are selected from: RANTES, MIP-1α, KC, MCP-1, IP-10 and MIG.

These and other aspects will become apparent from the following description of the preferred embodiment taken in conjunction with the following drawings, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present disclosure, the inventions of which can be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.

FIG. 1A shows: The structures of glycolipids with αGal or αGlc. 7DW8-5-Man is the only compound with αMan.

FIG. 1B shows: Synthesis of glycolipid analogues, reagents and conditions were as follows. a, Me2S, 2-Cl-pyridine, Tf2O, CH2Cl2, 4 & Aring; MS, −45° C., 16 h, 50-60%. b, Ph3P, pyr., H2O, 50° C., 9 h. c, fatty acids, EDC, HBTu, Et3N, CH2Cl2, 60%, two steps. d, AcOH—H2O 4:1, 65° C., 16 h. e, NaOME, MeCH—CH2Cl2 1:4, 5 h. f, Pd(OH)2, H2, MeOH—CH2Cl2 1:1, 5 h, 20-30%, three steps.

FIGS. 2A-D show: Glycolipid analogs with αGal were stronger immune modulators than those with αGlc in mice but weaker in humans. B6 wild type and Jα18 knockout mice (n=4) were i.v. injected with the indicated glycolipid (1 μg/mouse) or vehicle. Sera collected at 2 h and 18 h post-injection were analyzed for the secretion of cytokines like IFN-γ (2A) and IL-4 (2B). IFN-γ and IL-4 peaked at 18 hr and 2 hr post-injection, respectively. (2C) B6 WT mice treated with the indicated glycolipid (1 μg/mouse) or vehicle (1% DMSO in PBS) were sacrificed at 72 hr post-injection and their splenocytes were subjected to FACS analysis for the determination of total CD3+ cells. (2D) Human naïve Vα24+ iNKT cells were cultured with autologous immature CD14+ DCs pulsed with the indicated glycolipid at 100 ng/ml or DMSO on day 2. After antigen removal on day 3, human iNKT cells were cultured in the presence of IL-2. The number of expanded iNKT cells was counted using the Guava ViaCount reagent on day 9. Student t test was chosen to analyze the difference between 7DW8-5 and 7DW8-5-Glc with p<0.001, ***. Assays were performed in two different donors with similar trends.

FIGS. 3A-D show: The ternary interaction of CD1d-glycolipid complex with iNKT cells. (3A) DN3A4-1.2 Vα14+ iNKT hybridoma cells and (3B) 7DW8-5-expanded Vα24+ iNKT cells were incubated with various concentrations of the indicated dimeric mCD1d-glycolipid and hCD1d-glycolipid complexes for 30 min at 4° C., respectively. The level of bound complexes at the indicated concentration was detected by anti-mIgG1 secondary antibody and analyzed by flow cytometry. The relationship between the binding percentage and the concentration of CD1ddi-glycolipids complex was plotted in mice (3A) and humans (3B). KD values in mice (3C) and humans (3D) were calculated from Scatchard transformation of the plot (3A) and (3B), respectively. Assay was performed in duplicates.

FIGS. 4A-B show: mCD1d vs. hCD1d swapping assay. (4A) Murine DN3A4-1.2 Vα14+ iNKT hybridoma cells or (4B) C1-expanded Vα24+ iNKT cells were pulsed with the indicated glycolipid presented by either mCD1d (A20-CD1d cells) or hCD1d (HeLa-CD1d cells) at 1, 0.1, and 0.01 μg/ml. After 18 hr, the supernatants were harvested to measure IL-2 secretion by an ELISA assay (4A) or using Beadlyte® Human Cytokine kit and Luminex® 200™ reading system (4B). Assays were performed in triplicates. 8-5 was the abbreviation of 7DW8-5.

FIGS. 5A-E show: Computer modeling of the ternary complex of CD1d-GSL-iNKT TCR. (5A)/(5B) hydrogen bonds within the CD1d-C1-iNKT TCR complex of mice (5A) and humans (5B) were shown. Formation of hydrogen bonds was noted in the conserved residues, including human Asp80 (mouse Asp80), human Thr154 (mouse Thr156), human Asp151 (mouse Asp 153) of CD1d and human Gly96 (mouse Gly96) of iNKT TCR. Besides, mouse Asn30 as well as human Phe29 and Ser30 of iNKT TCR were the key residues forming H-bond interactions with 3′- and/or 4′-OHs of C1. (5C) the equatorial 4′-OH of glucose could compensate for the loss of Phe29 interaction by a stronger interaction with a crystal water, which was trapped by human iNKT TCR-Phe51 and hCD1d-Trp153. (5D) the higher energy from aromatic interactions could drive the acyl chain of C34 or C34-Glc to a lower position (near Cys12) of the A′ channel within CD1d, leading to a subtle perturbation to the orientation of the head group. (5E) The computed free energy of the ternary complex using Autodock4.2

FIGS. 6A-D show: Dose-dependent chemokine secretions triggered by 7DW8-5-Glc. B6 wild type mice were i.v. injected with 7DW8-5-Glc at 0.1 or 1 μg/mouse. Sera collected at 2 h and 18 h post-injection were analyzed for chemokine secretions such as IP-10 (6A), KC (6B), MCP-1 (6C), and MIP-1α (6D). These chemokines peaked at 2 hr post-injection.

FIGS. 7A-H show: iNKT-dependent productions of cytokines and chemokines. B6 wild type and Jα18 knockout mice were i.v. injected with the indicated glycolipids (1 μg/mouse) or vehicle. Sera collected at 2 h and 18 h post-injection were analyzed for cytokines like IL-2 (7A), IL-6 (7B), GM-CSF (7C) and TNFα (7D) as well as chemokines such as IP-10 (7E), MIG (7F), KC (7G) and MCP-1 (7H). Only MIG peaked at 18 hr post-injection, while the others peaked at 2 hr post-injection.

FIGS. 8A-F show: FACS analyses of WT mouse immune cells after the indicated glycolipid stimulation. B6 WT mice treated with the indicated glycolipid (1 μg/mouse) or vehicle (1% DMSO in PBS) were sacrificed at 72 hr post-injection and their splenocytes were subjected to FACS analysis. (8A) The total splenocytes, (8B) total CD11Chi cells, (8C) CD11Chi/CD80+ cells, (8D) CD11Chi/CD86+ cells, (8E) CD4+ T cells and (8F) CD8+ T cells.

FIGS. 9A-F show: FACS analyses of Jα18 KO mouse immune cells after the indicated glycolipid stimulation. B6 Jα18 KO mice treated with the indicated glycolipid (1 μg/mouse) or vehicle (% DMSO in PBS) were sacrificed at 72 hr post-injection and their splenocytes were subjected to FACS analysis. (9A) The total splenocytes, (9B) total CD11Chi cells, (9C) CD11Chi/CD80+ cells, (9D) CD11Chi/CD86+ cells, (9E) CD4+ T cells and (9F) CD8+ T cells (student t test: *, p<0.05, as compared to D)

FIGS. 10A-D show: Binding strengths of the binary complex between mCD1d and glycolipid. (10A, 10B) Different concentrations of mCD1d-glycolipid complexes coated on the ELISA plate were incubated with the saturated amount of L363 antibody conjugated with biotin, followed by streptavidin-HRP detection and ELISA measurement. (10A) The relationship between OD values reflecting L363 antibody binding and the concentration of CD1ddi-glycolipids complex was plotted. (10B) The dissociation constant (KD) between L363 antibody and the indicated mCD1d-glycolipid complex was calculated as described in Materials and methods. (10C) The relationship between OD values reflecting L363 antibody binding and the concentration of glycolipids was plotted. (10D) KD values of the binary complex were calculated from the linear regression of the Scatchard transformation of the L363 antibody binding curve (10C).

FIGS. 11A-D show: CD1d dimer staining of in vivo C1-pulsed splenocytes. B6 WT splenocytes (n=3) were harvested 3 days after injection with C1 (1 μg/mouse) and stained with CD3, CD45R and the indicated dimer complex conjugated with RPE for 1 hr at 4 degrees Celsius. (11A) CD3+/CD45R− cells were gated to analyze the dimer staining. (11B) unloaded dimer was used as the control. (11C) mCD1d dimer loaded with 7DW8-5-Glc stained 17.1±0.8% of C1-pulsed splenocytes. (11D) mCD1d dimer loaded with 7DW8-5 stained 36.2±5.0% of C1-pulsed splenocytes.

FIGS. 12A-C show: mCD1d vs. hCD1d swapping assay. C1-expanded Vα24+ iNKT cells were pulsed with the indicated glycolipid antigen presented by either mCD1d (A20-CD1d cells) or hCD1d (HeLa-CD1d cells) at 1, 0.1, and 0.01 μg/ml. After 18 hr, the supernatants were harvested for the measurement of IFN-γ (12A) and IL-4 (12B) secretions. (12C) The ratio of IFN-γ over IL-4 was calculated at different concentrations of glycolipids. The ratio of IFN-γ over IL-4 from different glycolipids were compared to that from C1 at the indicated concentrations by student t test (*, p<0.05; **, p<0.01; ***, p<0.001). Assays were performed in triplicates.

DETAILED DESCRIPTIONS

Natural killer T cells (NKTs) represent a subset of T lymphocytes with unique properties, including reactivity for natural or synthetic glycolipids presented by CD1d and expression of an invariant T cell antigen receptor (TCR) alpha chain. NKTs are different from functionally differentiated conventional αβ T cells in that they share properties of both natural killer cells and T cells are can rapidly produce both TH1-type and TH2-type responses upon stimulation with their ligands (innate immunity). The activation of NKTs paradoxically can lead either to suppression or stimulation of immune responses. For example, the production of TH1 cytokines is thought to promote cellular immunity with antitumor, antiviral/antibacterial, and adjuvant activities, whereas TH2 cytokine production is thought to subdue autoimmune diseases and promote antibody production. Because NKTs play a regulatory role in the immune system, they are attractive targets for immunotherapy.

As stated above, the present disclosure is based on the unexpected discovery that glycosphingolipids (GSLs) with α-glucose (α-Glc) exhibit stronger induction in humans (but weaker in mice) of cytokines and chemokines and expansion and/or activation of immune cells than those with α-galactose (α-Gal). Accordingly, methods and compositions comprising exemplary GSLs are provided herein.

The practice of the present invention will employ, unless otherwise indicated, conventional techniques of molecular biology, microbiology, recombinant DNA, and immunology, which are within the skill of the art. Such techniques are explained fully in the literature. See, for example, Molecular Cloning A Laboratory Manual, 2nd Ed., ed. by Sambrook, Fritsch and Maniatis (Cold Spring Harbor Laboratory Press, 1989); DNA Cloning, Volumes I and II (D. N. Glover ed., 1985); Culture Of Animal Cells (R. I. Freshney, Alan R. Liss, Inc., 1987); Immobilized Cells And Enzymes (IRL Press, 1986); B. Perbal, A Practical Guide To Molecular Cloning (1984); the treatise, Methods In Enzymology (Academic Press, Inc., N.Y.); Gene Transfer Vectors For Mammalian Cells (J. H. Miller and M. P. Calos eds., 1987, Cold Spring Harbor Laboratory); Methods In Enzymology, Vols. 154 and 155 (Wu et al. eds.), Immunochemical Methods In Cell And Molecular Biology (Mayer and Walker, eds., Academic Press, London, 1987); Antibodies: A Laboratory Manual, by Harlow and Lanes (Cold Spring Harbor Laboratory Press, 1988); and Handbook Of Experimental Immunology, Volumes I-IV (D. M. Weir and C. C. Blackwell, eds., 1986). In addition, the methods of making and using immune adjuvants are described in U.S. Pat. Nos. 7,488,491 and 7,928,077, the relevant disclosures of which are incorporated by reference herein.

As used herein, the term “lipid” refers to any fat-soluble (lipophilic) molecule that participates in cell signaling pathways. As used herein, the term “glycolipid” refers to a carbohydrate-attached lipid that serves as a marker for cellular recognition.

As used herein, the term “glycan” refers to a polysaccharide, or oligosaccharide. Glycan is also used herein to refer to the carbohydrate portion of a glycoconjugate, such as a glycoprotein, glycolipid, glycopeptide, glycoproteome, peptidoglycan, lipopolysaccharide or a proteoglycan. Glycans usually consist solely of O-glycosidic linkages between monosaccharides. For example, cellulose is a glycan (or more specifically a glucan) composed of beta-1,4-linked D-glucose, and chitin is a glycan composed of beta-1,4-linked N-acetyl-D-glucosamine. Glycans can be homo or heteropolymers of monosaccharide residues, and can be linear or branched. Glycans can be found attached to proteins as in glycoproteins and proteoglycans. They are generally found on the exterior surface of cells. O- and N-linked glycans are very common in eukaryotes but may also be found, although less commonly, in prokaryotes. N-Linked glycans are found attached to the R-group nitrogen (N) of asparagine in the sequon. The sequon is a Asn-X-Ser or Asn-X-Thr sequence, where X is any amino acid except proline.

As used herein, the term “glycoprotein” refers to a protein covalently modified with glycan(s). There are four types of glycoproteins: 1) N-linked glycoproteins, 2) O-linked glycoproteins (mucins), 3) glucosaminoglycans (GAGs, which are also called proteoglycans), 4) GPI-anchored. Most glycoproteins have structural micro-heterogeneity (multiple different glycan structures attached within the same glycosylation site), and structural macro-heterogeneity (multiple sites and types of glycan attachment).

As used herein, the term “analog” refers to a compound, e.g., a drug, whose structure is related to that of another compound but whose chemical and biological properties may be quite different.

As used herein, the term “antigen” is defined as any substance capable of eliciting an immune response.

As used herein, the term “pathogen” is a biological agent that causes disease or illness to it's host. The body contains many natural defenses against some of the common pathogens (such as Pneumocystis) in the form of the human immune system.

As used herein, the term “immunogen” refers to an antigen or a substance capable of inducing production of an antigen, such as a DNA vaccine.

As used herein, the term “immunogenicity” refers to the ability of an immunogen, antigen, or vaccine to stimulate an immune response.

As used herein, the term “immunotherapy” refers to an array of treatment strategies based upon the concept of modulating the immune system to achieve a prophylactic and/or therapeutic goal.

Other Definitions

The terms “treating” and “treatment” as used herein refer to the administration of an agent or formulation to a clinically symptomatic individual afflicted with an adverse condition, disorder, or disease, so as to effect a reduction in severity and/or frequency of symptoms, eliminate the symptoms and/or their underlying cause, and/or facilitate improvement or remediation of damage. The terms “preventing” and “prevention” refer to the administration of an agent or composition to a clinically asymptomatic individual who is susceptible to a particular adverse condition, disorder, or disease, and thus relates to the prevention of the occurrence of symptoms and/or their underlying cause. Unless otherwise indicated herein, either explicitly or by implication, if the term “treatment” (or “treating”) is used without reference to possible prevention, it is intended that prevention be encompassed as well.

“Optional” or “optionally present”—as in an “optional substituent” or an “optionally present additive” means that the subsequently described component (e.g., substituent or additive) may or may not be present, so that the description includes instances where the component is present and instances where it is not.

By “pharmaceutically acceptable” is meant a material that is not biologically or otherwise undesirable, e.g., the material may be incorporated into a formulation of the invention without causing any undesirable biological effects or interacting in a deleterious manner with any of the other components of the dosage form formulation. However, when the term “pharmaceutically acceptable” is used to refer to a pharmaceutical excipient, it is implied that the excipient has met the required standards of toxicological and manufacturing testing and/or that it is included on the Inactive Ingredient Guide prepared by the U.S. Food and Drug Administration. As explained in further detail infra, “pharmacologically active” (or simply “active”) as in a “pharmacologically active” derivative or analog refers to derivative or analog having the same type of pharmacological activity as the parent agent.

As used herein, the term “immunogen” refers to an antigen or a substance capable of inducing production of an antigen, such as a DNA vaccine.

As used herein, the term “immunogenicity” refers to the ability of an immunogen, antigen, or vaccine to stimulate an immune response.

As used herein, the term “immunotherapy” refers to an array of treatment strategies based upon the concept of modulating the immune system to achieve a prophylactic and/or therapeutic goal.

As used herein, the term “cytokine” refers to any of numerous small, secreted proteins that regulate the intensity and duration of the immune response by affecting immune cells differentiation process usually involving changes in gene expression by which a precursor cell becomes a distinct specialized cell type. Cytokines have been variously named as lymphokines, interleukins, and chemokines, based on their presumed function, cell of secretion, or target of action. For example, some common interleukins include, but are not limited to, IL-12, IL-18, IL-2, IFN-γ, TNF, IL-4, IL-10, IL-13, IL-21 and TGF-β. “Cytokine” is a generic term for a group of proteins released by one cell population which act on another cell population as intercellular mediators. Examples of such cytokines are lymphokines, monokines, and traditional polypeptide hormones. Included among the cytokines are interferons (IFN, notably IFN-γ), interleukins (IL, notably IL-1, IL-2, IL-4, IL-10, IL-12), colony stimulating factors (CSF), thrombopoietin (TPO), erythropoietin (EPO), leukemia inhibitory factor (LIF), kit-ligand, growth hormones (GH), insulin-like growth factors (IGF), parathyroid hormone, thyroxine, insulin, relaxin, follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), leutinizing hormone (LH), hematopoietic growth factor, hepatic growth factor, fibroblast growth factors (FGF), prolactin, placental lactogen, tumor necrosis factors (TNF), mullerian-inhibiting substance, mouse gonadotropin-associated peptide, inhibin, activin, vascular endothelial growth factor (VEGF), integrin, nerve growth factors (NGF), platelet growth factor, transforming growth factors (TGF), osteoinductive factors, etc.

As used herein, the term “chemokine” refers to any of various small chemotactic cytokines released at the site of infection that provide a means for mobilization and activation of lymphocytes. Chemokines attract leukocytes to infection sites. Chemokines have conserved cysteine residues that allow them to be assigned to four groups. The groups, with representative chemokines, are C-C chemokines (RANTES, MCP-1, MIP-1α, and MIP-1β), C-X-C chemokines (IL-8), C chemokines (Lymphotactin), and CXXXC chemokines (Fractalkine).

As used herein, the term “epitope” is defined as the parts of an antigen molecule which contact the antigen binding site of an antibody or a T cell receptor.

To further explain differential binding avidities of the ternary complex in mice and men, computer modeling was performed based on the x-ray structures of murine and human CD1d-αGalCer-iNKT TCR complexes, respectively (PDB access code 3HUJ, 3QUX, 3QUY, 3QUZ, and 3HE6).²⁷⁻²⁹ (27) Borg, N. A.; Wun, K. S.; Kjer-Nielsen, L.; Wilce, M. C.; Pellicci, D. G.; Koh, R.; Besra, G. S.; Bharadwaj, M.; Godfrey, D. I.; McCluskey, J.; Rossjohn, J. Nature 2007, 448, 44; (28) Pellicci, D. G.; Patel, O.; Kjer-Nielsen, L.; Pang, S. S.; Sullivan, L. C.; Kyparissoudis, K.; Brooks, A. G.; Reid, H. H.; Gras, S.; Lucet, I. S.; Koh, R.; Smyth, M. J.; Mallevaey, T.; Matsuda, J. L.; Gapin, L.; McCluskey, J.; Godfrey, D. I.; Rossjohn, J. Immunity 2009, 31, 47; and (29) Aspeslagh, S.; Li, Y.; Yu, E. D.; Pauwels, N.; Trappeniers, M.; Girardi, E.; Decruy, T.; Van Beneden, K.; Venken, K.; Drennan, M.; Leybaert, L.; Wang, J.; Franck, R. W.; Van Calenbergh, S.; Zajonc, D. M.; Elewaut, D. EMBO J. 2011, 30, 2294.

As used herein, the term “vaccine” refers to a preparation that contains an antigen, consisting of whole disease-causing organisms (killed or weakened) or components of such organisms, such as proteins, peptides, or polysaccharides, that is used to confer immunity against the disease that the organisms cause. Vaccine preparations can be natural, synthetic or derived by recombinant DNA technology.

As used herein, the terms “immunologic adjuvant” refers to a substance used in conjunction with an immunogen which enhances or modifies the immune response to the immunogen. Specifically, the terms “adjuvant” and “immunoadjuvant” are used interchangeably in the present invention and refer to a compound or mixture that may be non-immunogenic when administered to a host alone, but that augments the host's immune response to another antigen when administered conjointly with that antigen. Adjuvant-mediated enhancement and/or extension of the duration of the immune response can be assessed by any method known in the art including without limitation one or more of the following: (i) an increase in the number of antibodies produced in response to immunization with the adjuvant/antigen combination versus those produced in response to immunization with the antigen alone; (ii) an increase in the number of T cells recognizing the antigen or the adjuvant; and (iii) an increase in the level of one or more Type I cytokines.

Exemplary adjuvants of the invention comprise compounds which can be represented by a general Formula 1.

Preferably, the exemplary adjuvant of the invention is pharmaceutically acceptable for use in humans.

The adjuvant of the invention can be administered as part of a pharmaceutical or vaccine composition comprising an antigen or as a separate formulation, which is administered conjointly with a second composition containing an antigen. In any of these compositions glycosphingolipids (GSLs) with α-glucose (α-Glc) can be combined with other adjuvants and/or excipients/carriers. These other adjuvants include, but are not limited to, oil-emulsion and emulsifier-based adjuvants such as complete Freund's adjuvant, incomplete Freund's adjuvant, MF59, or SAF; mineral gels such as aluminum hydroxide (alum), aluminum phosphate or calcium phosphate; microbially-derived adjuvants such as cholera toxin (CT), pertussis toxin, Escherichia coli heat-labile toxin (LT), mutant toxins (e.g., LTK63 or LTR72), Bacille Calmette-Guerin (BCG), Corynebacterium parvum, DNA CpG motifs, muramyl dipeptide, or monophosphoryl lipid A; particulate adjuvants such as immunostimulatory complexes (ISCOMs), liposomes, biodegradable microspheres, or saponins (e.g., QS-21); cytokines such as IFN-γ, IL-2, IL-12 or GM-CSF; synthetic adjuvants such as nonionic block copolymers, muramyl peptide analogues (e.g., N-acetyl-muramyl-L-threonyl-D-isoglutamine [thr-MDP], N-acetyl-nor-muramyl-L-alanyl-D-isoglutamine, N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanine-2-[1′-2′-dipalmitoyl-sn-glycero-3-hydroxyphosphoryloxy]-ethylamine), polyphosphazenes, or synthetic polynucleotides, and surface active substances such as lysolecithin, pluronic polyols, polyanions, peptides, hydrocarbon emulsions, or keyhole limpet hemocyanins (KLH). Preferably, these additional adjuvants are also pharmaceutically acceptable for use in humans.

Within the meaning of the present invention, the term “conjoint administration or co-administration” is used to refer to administration of an immune adjuvant and an antigen simultaneously in one composition, or simultaneously in different compositions, or sequentially. For the sequential administration to be considered “conjoint”, however, the antigen and adjuvant must be administered separated by a time interval that still permits the adjuvant to augment the immune response to the antigen. For example, when the antigen is a polypeptide, the antigen and adjuvant are administered on the same day, preferably within an hour of each other, and most preferably simultaneously. However, when nucleic acid is delivered to the subject and the polypeptide antigen is expressed in the subject's cells, the adjuvant is administered within 24 hours of nucleic acid administration, preferably within 6 hours.

As used herein, the term “immunogenic” means that an agent is capable of eliciting a humoral or cellular immune response, and preferably both. An immunogenic entity is also antigenic. An immunogenic composition is a composition that elicits a humoral or cellular immune response, or both, when administered to an animal having an immune system.

The term “antigen” refers to any agent (e.g., protein, peptide, polysaccharide, glycoprotein, glycolipid, nucleic acid, or combination thereof) that, when introduced into a host, animal or human, having an immune system (directly or upon expression as in, e.g., DNA vaccines), is recognized by the immune system of the host and is capable of eliciting an immune response. As defined herein, the antigen-induced immune response can be humoral or cell-mediated, or both. An agent is termed “antigenic” when it is capable of specifically interacting with an antigen recognition molecule of the immune system, such as an immunoglobulin (antibody) or T cell antigen receptor (TCR). Within the meaning of the present invention, the antigens are preferably “surface antigens”, i.e., expressed naturally on the surface of a pathogen, or the surface of an infected cell, or the surface of a tumor cell. A molecule that is antigenic need not be itself immunogenic, i.e., capable of eliciting an immune response without an adjuvant or carrier. As used herein, the term “antigen specific” refers to a property of a cell population such that supply of a particular antigen, or a fragment of the antigen, results in specific cell characteristic.

The term “epitope” or “antigenic determinant” refers to any portion of an antigen recognized either by B cells, or T cells, or both. Preferably, interaction of such epitope with an antigen recognition site of an immunoglobulin (antibody) or T cell antigen receptor (TCR) leads to the induction of antigen-specific immune response. T cells recognize proteins only when they have been cleaved into smaller peptides and are presented in a complex called the “major histocompatability complex (MHC)” located on another cell's surface. There are two classes of MHC complexes-class I and class II, and each class is made up of many different alleles. Class I MHC complexes are found on virtually every cell and present peptides from proteins produced inside the cell. Thus, class I MHC complexes are useful for killing cells infected by viruses or cells which have become cancerous as the result of expression of an oncogene. T cells which have a protein called CD8 on their surface, bind specifically to the MHC class I/peptide complexes via the T cell receptor (TCR). This leads to cytolytic effector activities. Class II MHC complexes are found only on antigen-presenting cells (APC) and are used to present peptides from circulating pathogens which have been endocytosed by APCs. T cells which have a protein called CD4 bind to the MHC class II/peptide complexes via TCR. This leads to the synthesis of specific cytokines which stimulate an immune response. To be effectively recognized by the immune system via MHC class I presentation, an antigenic polypeptide has to contain an epitope of at least about 8 to 10 amino acids, while to be effectively recognized by the immune system via MHC class II presentation, an antigenic polypeptide has to contain an epitope of at least about 13 to 25 amino acids. See, e.g., Fundamental Immunology, 3^(rd) Edition, W. E. Paul ed., 1999, Lippincott-Raven Publ.

The term “species-specific” antigen refers to an antigen that is only present in or derived from a particular species. Thus, the term “malaria-derived” or “malaria-specific” antigen refers to a natural (e.g., irradiated sporozoites) or synthetic (e.g., chemically produced multiple antigen peptide [MAP] or recombinantly synthesized polypeptide) antigen comprising at least one epitope (B cell and/or T cell) derived from any one of the proteins constituting plasmodium (said plasmodium being without limitation P. falciparum, P. vivax, P. malariae, P. ovale, P. reichenowi, P. knowlesi, P. cynomolgi, P. brasilianum, P. yoelii, P. berghei, or P. chabaudi) and comprising at least 5-10 amino acid residues. A preferred plasmodial protein for antigen generation is circumsporozoite (CS) protein, however, other proteins can be also used, e.g., Thrombospondin Related Adhesion (Anonymous) protein (TRAP), also called Sporozoite Surface Protein 2 (SSP2), LSA I, hsp70, SALSA, STARP, Hep17, MSA, RAP-1, RAP-2, etc.

The term “vaccine” refers to a composition (e.g., protein or vector such as, e.g., an adenoviral vector, Sindbis virus vector, or pox virus vector) that can be used to elicit protective immunity in a recipient. It should be noted that to be effective, a vaccine of the invention can elicit immunity in a portion of the immunized population, as some individuals may fail to mount a robust or protective immune response, or, in some cases, any immune response. This inability may stem from the individual's genetic background or because of an immunodeficiency condition (either acquired or congenital) or immunosuppression (e.g., due to treatment with chemotherapy or use of immunosuppressive drugs, e.g., to prevent organ rejection or suppress an autoimmune condition). Vaccine efficacy can be established in animal models.

The term “DNA vaccine” is an informal term of art, and is used herein to refer to a vaccine delivered by means of a recombinant vector. An alternative, and more descriptive term used herein is “vector vaccine” (since some potential vectors, such as retroviruses and lentiviruses are RNA viruses, and since in some instances non-viral RNA instead of DNA is delivered to cells through the vector). Generally, the vector is administered in vivo, but ex vivo transduction of appropriate antigen presenting cells, such as dendritic cells (DC), with administration of the transduced cells in vivo, is also contemplated.

The term “treat” is used herein to mean to relieve or alleviate at least one symptom of a disease in a subject. Within the meaning of the present invention, the term “treat” may also mean to prolong the prepatency, i.e., the period between infection and clinical manifestation of a disease. Preferably, the disease is either infectious disease (e.g., viral, bacterial, parasitic, or fungal) or malignancy (e.g., solid or blood tumors such as sarcomas, carcinomas, gliomas, blastomas, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, lymphoma, leukemia, melanoma, etc.).

The term “protect” is used herein to mean prevent or treat, or both, as appropriate, development or continuance of a disease in a subject. Within the meaning of the present invention, the disease can be selected from the group consisting of infection (e.g., viral, bacterial, parasitic, or fungal) and/or malignancy (e.g., solid or blood tumors such as sarcomas, carcinomas, gliomas, blastomas, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, lymphoma, leukemia, melanoma, etc.). For example, according to the present invention, a therapeutic administration of a tumor-specific antigen conjointly with an adjuvant comprising exemplary agents of Formula 1 can enhance an anti-tumor immune response leading to slow-down in tumor growth and metastasis or even tumor regression.

The term “protective immunity” refers to an immune response in a host animal (either active/acquired or passive/innate, or both) which leads to inactivation and/or reduction in the load of said antigen and to generation of long-lasting immunity (that is acquired, e.g., through production of antibodies), which prevents or delays the development of a disease upon repeated exposure to the same or a related antigen. A “protective immune response” comprises a humoral (antibody) immunity or cellular immunity, or both, effective to, e.g., eliminate or reduce the load of a pathogen or infected cell (or produce any other measurable alleviation of the infection), or to reduce a tumor burden in an immunized (vaccinated) subject. Within the meaning of the present invention, protective immunity may be partial.

Immune systems are classified into two general systems, the “innate” or “natural” immune system and the “acquired” or “adaptive” immune system. It is thought that the innate immune system initially keeps the infection under control, allowing time for the adaptive immune system to develop an appropriate response. Recent studies have suggested that the various components of the innate immune system trigger and augment the components of the adaptive immune system, including antigen-specific B and T lymphocytes (Fearon and Locksley, supra; Kos, 1998, Immunol. Res., 17: 303; Romagnani, 1992, Immunol. Today, 13: 379; Banchereau and Steinman, 1988, Nature, 392: 245).

The term “innate immunity” or “natural immunity” refers to innate immune responses that are not affected by prior contact with the antigen. Cells of the innate immune system, including macrophages and dendritic cells (DC), take up foreign antigens through pattern recognition receptors, combine peptide fragments of these antigens with MHC class I and class II molecules, and stimulate naive CD8⁺ and CD4⁺ T cells respectively (Banchereau and Steinman, supra; Holmskov et al., 1994, Immunol. Today, 15: 67; Ulevitch and Tobias, 1995, Annu. Rev. Immunol., 13: 437). Professional antigen-presenting cells (APC) communicate with these T cells leading to the differentiation of naive CD4⁺ T cells into T-helper 1 (Th1) or T-helper 2 (Th2) lymphocytes that mediate cellular and humoral immunity, respectively (Trinchieri, 1995, Annu. Rev. Immunol., 13: 251; Howard and O'Garra, 1992, Immunol. Today, 13: 198; Abbas et al., 1996, Nature, 383: 787; Okamura et al., 1998, Adv. Immunol., 70: 281; Mosmann and Sad, 1996, Immunol. Today, 17: 138; O'Garra, 1998, Immunity, 8: 275).

The term “acquired immunity” or “adaptive immunity” is used herein to mean active or passive, humoral or cellular immunity that is established during the life of an animal, is specific for the inducing antigen, and is marked by an enhanced response on repeated encounters with said antigen. A key feature of the T lymphocytes of the adaptive immune system is their ability to detect minute concentrations of pathogen-derived peptides presented by MHC molecules on the cell surface.

As used herein, the term “augment the immune response” means enhancing or extending the duration of the immune response, or both. When referred to a property of an agent (e.g., adjuvant), the term “[able to] augment the immunogenicity” refers to the ability to enhance the immunogenicity of an antigen or the ability to extend the duration of the immune response to an antigen, or both.

The phrase “enhance immune response” within the meaning of the present invention refers to the property or process of increasing the scale and/or efficiency of immunoreactivity to a given antigen, said immunoreactivity being either humoral or cellular immunity, or both. An immune response is believed to be enhanced, if any measurable parameter of antigen-specific immunoreactivity (e.g., antibody titer, T cell production) is increased at least two-fold, preferably ten-fold, most preferably thirty-fold.

The term “therapeutically effective” applied to dose or amount refers to that quantity of a compound or pharmaceutical composition or vaccine that is sufficient to result in a desired activity upon administration to a mammal in need thereof. As used herein with respect to adjuvant—and antigen-containing compositions or vaccines, the term “therapeutically effective amount/dose” is used interchangeably with the term “immunogenically effective amount/dose” and refers to the amount/dose of a compound (e.g., an antigen and/or an adjuvant comprising glycosphingolipids (GSLs) with α-glucose (α-Glc) or pharmaceutical composition or vaccine that is sufficient to produce an effective immune response upon administration to a mammal.

The phrase “pharmaceutically acceptable”, as used in connection with compositions of the invention, refers to molecular entities and other ingredients of such compositions that are physiologically tolerable and do not typically produce untoward reactions when administered to a human. Preferably, as used herein, the term “pharmaceutically acceptable” means approved by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in mammals, and more particularly in humans.

The term “carrier” applied to pharmaceutical or vaccine compositions of the invention refers to a diluent, excipient, or vehicle with which a compound (e.g., an antigen and/or an adjuvant comprising glycosphingolipids (GSLs) with α-glucose (α-Glc)) is administered. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Water or aqueous solution, saline solutions, and aqueous dextrose and glycerol solutions are preferably employed as carriers, particularly for injectable solutions. Suitable pharmaceutical carriers are described in “Remington's Pharmaceutical Sciences” by E. W. Martin, 18^(th) Edition.

The term “native antibodies” or “immunoglobulins” refers to usually heterotetrameric glycoproteins of about 150,000 daltons, composed of two identical light (L) chains and two identical heavy (H) chains. Each light chain is linked to a heavy chain by one covalent disulfide bond, while the number of disulfide linkages varies between the heavy chains of different immunoglobulin isotypes. Each heavy and light chain also has regularly spaced intrachain disulfide bridges. Each heavy chain has at one end a variable domain (VH) followed by a number of constant domains. Each light chain has a variable domain (VL) at one end and a constant domain at its other end; the constant domain of the light chain is aligned with the first constant domain of the heavy chain, and the light chain variable domain is aligned with the variable domain of the heavy chain. Particular amino acid residues are believed to form an interface between the light and heavy chain variable domains (Clothia et al., J Mol. Biol., 186: 651-663, 1985; Novotny and Haber, Proc. Natl. Acad. Sci. USA, 82: 4592-4596, 1985).

The term “antibody” or “Ab” is used in the broadest sense and specifically covers not only native antibodies but also single monoclonal antibodies (including agonist and antagonist antibodies), antibody compositions with polyepitopic specificity, as well as antibody fragments (e.g., Fab, F(ab′)2, scFv and Fv), so long as they exhibit the desired biological activity.

As used herein, the term “CD1d” refers to a member of the CD1 (cluster of differentiation 1) family of glycoproteins expressed on the surface of various human antigen-presenting cells. CD1d presented lipid antigens activate natural killer T cells. CD1d has a deep antigen-binding groove into which glycolipid antigens bind. CD1d molecules expressed on dendritic cells can bind and present glycolipids.

As used herein, the term “adaptive immune system” refers to highly specialized, systemic cells and processes that eliminate pathogenic challenges. The cells of the adaptive immune system are a type of leukocyte, called a lymphocyte. B cells and T cells are the major types of lymphocytes.

As used herein, the term “T cells” and “Ts” refer to a group of white blood cells known as lymphocytes, that play a central role in cell-mediated immunity. T cells can be distinguished from other lymphocyte types, such as B cells and NKs by the presence of a special receptor on their cell surface called the T cell receptor (TCR). Several different subsets of T cells have been described, each with a distinct function. Helper T (T_(H)) Cells are the “middlemen” of the adaptive immune system. Once activated, they divide rapidly and secrete small proteins called cytokines that regulate or “help” the immune response. Depending on the cytokine signals received, these cells differentiate into T_(H)1, T_(H)2, T_(H)17, or one of other subsets, which secrete different cytokines.

As used herein, the term “antigen-presenting cell” (APC) refers to a cell that displays foreign antigen complexed with major histocompatibility complex (MHC) on its surface. T-cells may recognize this complex using their TCR. APCs fall into two categories: professional or non-professional. Dendritic cells (DCs) fall under the professional category and are capable of presenting antigen to T cells, in the context of CD1. In an exemplary implementation, the DCs utilized in the methods of this disclosure may be of any of several DC subsets, which differentiate from, in one implementation, lymphoid or, in another implementation, myeloid bone marrow progenitors.

As used herein, the term “naïve cell” refers to an undifferentiated immune system cell, for example a CD4 T-cell, that has not yet specialized to recognize a specific pathogen.

As used herein, the term “natural killer cells” and “NKs” refers to a class of lymphoid cells which are activated by interferons to contribute to innate host defense against viruses and other intracellular pathogens.

As used herein, the term “natural killer T cells” (NKTs) refers to a subset of T cells that share characteristics/receptors with both conventional Ts and NKs. Many of these cells recognize the non-polymorphic CD1d molecule, an antigen-presenting molecule that binds self- and foreign lipids and glycolipids. The TCR of the NKTs are able to recognize glycolipid antigens presented (chaperoned) by a CD1d molecule. A major response of NKTs is rapid secretion of cytokines, including IL-4, IFN-γ and IL-10 after stimulation and thus influence diverse immune responses and pathogenic processes. The NKTs may be a homogenous population or a heterogeneous population. In one exemplary implementation, the population may be “non-invariant NKTs”, which may comprise human and mouse bone marrow and human liver T cell populations that are, for example, CD1d-reactive noninvariant T cells which express diverse TCRs, and which can also produce a large amount of IL-4 and IFN-γ. The best known subset of CD1d-dependent NKTs expresses an invariant TCR-alpha (TCR-α) chain. These are referred to as type I or invariant NKTs (iNKTs). These cells are conserved between humans (Vα24i NKTs) and mice (Vα14i NKTs) and are implicated in many immunological processes.

As used herein, the term “cytokine” refers to any of numerous small, secreted proteins that regulate the intensity and duration of the immune response by affecting immune cells differentiation process usually involving changes in gene expression by which a precursor cell becomes a distinct specialized cell type. Cytokines have been variously named as lymphokines, interleukins, and chemokines, based on their presumed function, cell of secretion, or target of action. For example, some common interleukins include, but are not limited to, IL-12, IL-18, IL-2, IFN-γ, TNF, IL-4, IL-10, IL-13, IL-21 and TGF-β.

As used herein, the term “chemokine” refers to any of various small chemotactic cytokines released at the site of infection that provide a means for mobilization and activation of lymphocytes. Chemokines attract leukocytes to infection sites. Chemokines have conserved cysteine residues that allow them to be assigned to four groups. The groups, with representative chemokines, are C-C chemokines (RANTES, MCP-1, MIP-1α, and MIP-1β), C-X-C chemokines (IL-8), C chemokines (Lymphotactin), and CXXXC chemokines (Fractalkine).

As used herein, the term “T_(H)2-type response” refers to a pattern of cytokine expression such that certain types of cytokines, interferons, chemokines are produced. Typical T_(H)2 cytokines include, but are not limited to, IL-4, IL-5, IL-6 and IL-10.

As used herein, the term “T_(H)1-type response” refers to a pattern of cytokine expression such that certain types of cytokines, interferons, chemokines are produced. Typical T_(H)1 cytokines include, but are not limited to, IL-2, IFN-γ, GM-CSF and TNF-β.

As used herein, the term “T_(H)1 biased” refers to am immunogenic response in which production of T_(H)1 cytokines and/or chemokines is increased to a greater extent than production of T_(H)2 cytokines and/or chemokines.

As used herein, the term “antimicrobial” refers to a substance that kills or inhibits the growth of microbes such as bacteria, fungi, or viruses.

As used herein, the term “toxoid” refers to a bacterial toxin whose toxicity has been weakened or suppressed either by chemical (formalin) or heat treatment, while other properties, typically immunogenicity, are maintained. Toxoids are used in vaccines as they induce an immune response to the original toxin or increase the response to another antigen. For example, the tetanus toxoid is derived from the tetanospasmin produced by Clostridium tetani and causing tetanus. The tetanus toxoid is used by many plasma centers in the United States for the development of plasma rich vaccines.

As used herein, the term “DNA vaccine” refers to a DNA construct that is introduced into cells and subsequently translated into specific antigenic proteins.

As used herein, the term “plasmid” refers to an extrachromosomal circular DNA capable of replicating, which may be used as a cloning vector.

As used herein, the term “microorganism” and “microbe” refers to an organism that is microscopic (too small to be seen by the naked human eye). Microorganisms are incredibly diverse and include, but are not limited to, bacteria and fungi.

As used herein, the term “adjuvant or immunologic adjuvant” refers to a substance used in conjunction with an immunogen which enhances or modifies the immune response to the immunogen. In an exemplary compound/analogs of the present disclosure are used as immunologic adjuvants to modify or augment the effects of a vaccine by stimulating the immune system of a patient who is administered the vaccine to respond to the vaccine more vigorously.

As used herein, the term “alum adjuvant” refers to an aluminum salt with immune adjuvant activity. This agent adsorbs and precipitates protein antigens in solution; the resulting precipitate improves vaccine immunogenicity by facilitating the slow release of antigen from the vaccine depot formed at the site of inoculation.

As used herein, the term “anti-tumor immunotherapy active agent” refers to an exemplary compound/analog of the present disclosure that inhibits, reduces and/or eliminates tumors.

As used herein, the term “granulocyte-macrophage colony-stimulating factor” (GM-CSF) refers to a cytokine which serves as a colony-stimulating factor that stimulates production of white blood cells, particularly granulocytes (neutrophils, basophils, and eosinophils), macrophages, and cells in the bone marrow that are precursors of platelets.

As used herein, the term “antigen specific” refers to a property of a cell population such that supply of a particular antigen, or a fragment of the antigen, results in specific cell proliferation.

As used herein, the term “Flow cytometry” or “FACS” means a technique for examining the physical and chemical properties of particles or cells suspended in a stream of fluid, through optical and electronic detection devices.

Amino acid residues in peptides shall hereinafter be abbreviated as follows: P Phenylalanine is Phe or F; Leucine is Leu or L; Isoleucine is Ile or I; Methionine is Met or M; Valine is Val or V; Serine is Ser or S; Proline is Pro or P; Threonine is Thr or T; Alanine is Ala or A; Tyrosine is Tyr or Y; Histidine is His or H; Glutamine is Gln or Q; Asparagine is Asn or N; Lysine is Lys or K; Aspartic Acid is Asp or D; Glutamic Acid is Glu or E; Cysteine is Cys or C; Tryptophan is Trp or W; Arginine is Arg or R; and Glycine is Gly or G. For further description of amino acids, please refer to Proteins: Structure and Molecular Properties by Creighton, T. E., W. H. Freeman & Co., New York 1983.

Mammalian and mycobacterial lipids are known to be presented by human CD1a, CD1b, CD1c, and CD1d. α-Galactosyl ceramide, a lipid found in the marine sponge Agelas mauritianus, has been the most extensively studied ligand for CD1d. It has been shown that in vitro stimulation of mouse spleen cells by α-GalCer led to the proliferation of NKTs and production of both IFN-□ and IL-4, a T_(H)1-type and T_(H)2-type response, respectively. Murine studies have shown that cells can be rapidly activated by immature dendritic cells (iDCs) bearing α-GalCer and that the activated iNKTs can in turn induce full maturation of DCs.

Uses of Adjuvants Comprising Glycosphingolipids (GSLs) with α-Glucose (α-Glc)

In one aspect, the present invention provides a method for augmenting an immunogenicity of an antigen in a mammal, comprising administering said antigen conjointly with an adjuvant composition comprising a glycosphingolipids (GSLs) with α-glucose (α-Glc) of Formula 1. According to the present invention, the use of glycosphingolipids (GSLs) with α-glucose (α-Glc) as an adjuvant results in an enhancement and/or extension of the duration of the protective immunity induced by the antigen. For example, as disclosed herein, conjoint administration of glycosphingolipids (GSLs) with α-glucose (α-Glc) with peptides corresponding to T cell or B cell epitopes of tumor or viral antigens, or DNA constructs expressing these antigens enhances antigen-specific immune responses.

The glycosphingolipids (GSLs) with α-glucose (α-Glc)-containing adjuvant of the invention can be conjointly administered with any antigen, in particular, with antigens derived from infectious agents or tumors.

The immunostimulating effects both in mice and humans may depend on the expression of CD1d molecules and are mediated by NKT cells. Indeed, the instant invention demonstrates that adjuvant activity is attributed at least in part to its ability to enhance and/or extend NKT-mediated antigen-specific Th1-type T cell responses and CD8+ T cell (or Tc) responses.

From an immunotherapy view point, glycosphingolipids (GSLs) with α-glucose (α-Glc) activation of the NKT cell system appears to have distinct advantages over the other mechanisms for the following reasons: (a) the level of cytotoxicity of activated NKT cells is very high and effective against a wide variety of tumor cells or infected cells; (b) the activation of NKT cells by glycosphingolipids (GSLs) with α-glucose (α-Glc) is totally dependent on a CD1d molecule, which is monomorphic among individuals (Porcelli, Adv. Immunol., 59: 1-98, 1995), indicating that glycosphingolipids (GSLs) with α-glucose (α-Glc)-containing adjuvants can be utilized by all patients, regardless of MHC haplotype; (c) antigen-presenting functions of DC and NKT activation of human patients can be evaluated before immunotherapy by the in vivo assays in mice using Vα14 NKT cell status as an indicator.

According to the present invention, an adjuvant comprising glycosphingolipids (GSLs) with α-glucose (α-Glc) of Formula 1 and antigen can be administered either as two separate formulations or as part of the same composition. If administered separately, the adjuvant and antigen can be administered either sequentially or simultaneously. As disclosed herein, simultaneous administration of glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant with the antigen is preferred and generally allows to achieve the most efficient immunostimulation.

As the glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant of the invention exerts its immunostimulatory activity in combination with a plurality of different antigens, it is therefore useful for both preventive and therapeutic applications. Accordingly, in a further aspect, the invention provides a prophylactic and/or therapeutic method for treating a disease in a mammal comprising conjointly administering to said mammal an antigen and an adjuvant comprising a glycosphingolipids (GSLs) with α-glucose (α-Glc) of Formula 1. This method can be useful, e.g., for protecting against and/or treating various infections as well as for treating various neoplastic diseases.

Immunogenicity enhancing methods of the invention can be used to combat infections, which include, but are not limited to, parasitic infections (such as those caused by plasmodial species, etc.), viral infections (such as those caused by influenza viruses, leukemia viruses, immunodeficiency viruses such as HIV, papilloma viruses, herpes virus, hepatitis viruses, measles virus, poxviruses, mumps virus, cytomegalovirus [CMV], Epstein-Barr virus, etc.), bacterial infections (such as those caused by staphylococcus, streptococcus, pneumococcus, Neisseria gonorrhea, Borrelia, pseudomonas, etc.), and fungal infections (such as those caused by candida, trichophyton, ptyrosporum, etc.).

Methods of the invention are also useful in treatment of various cancers, which include without limitation fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendothelio-sarcoma, synovioma, mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon carcinoma, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, lymphoma, leukemia, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinoma, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, testicular tumor, lung carcinoma, small cell lung carcinoma, bladder carcinoma, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, melanoma, neuroblastoma, and retinoblastoma.

As further disclosed herein, maximal efficiency of the immunogenicity enhancing methods of present invention is attained when an antigen and glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant are administered simultaneously.

The methods of the invention can be used in conjunction with other treatments. For example, an anti-cancer treatment using tumor-specific antigen and glycosphingolipids (GSLs) with α-glucose (α-Glc)-containing adjuvant of the present invention can be used in combination with chemotherapy and/or radiotherapy and/or IL-12 treatment. Anti-viral vaccines comprising glycosphingolipids (GSLs) with α-glucose (α-Glc)-containing adjuvant can be used in combination with IFN-αtreatment.

Glycosphingolipids (GSLs) with α-Glucose (α-Glc)-Containing Pharmaceutical and Vaccine Compositions

In conjunction with the methods of the present invention, also provided are pharmaceutical and vaccine compositions comprising an immunogenically effective amount of an antigen and immunogenically effective amount of an adjuvant comprising glycosphingolipids (GSLs) with α-glucose (α-Glc) as well as, optionally, an additional immunostimulant, carrier or excipient (preferably all pharmaceutically acceptable). Said antigen and adjuvant can be either formulated as a single composition or as two separate compositions, which can be administered simultaneously or sequentially.

Adjuvants of the invention comprise compounds which belong to the class of sphingoglycolipids, specifically glycosphingolipids (GSLs) with α-glucose (α-Glc), which can be represented by a general Formula 1:

The antigens used in immunogenic (e.g., vaccine) compositions of the instant invention can be derived from a eukaryotic cell (e.g., tumor, parasite, fungus), bacterial cell, viral particle, or any portion thereof (e.g. attenuated viral particles or viral components). In the event the material to which the immunogenic response is to be directed is poorly antigenic, it may be additionally conjugated to a carrier molecule such as albumin or hapten, using standard covalent binding techniques, for example, with one of the several commercially available reagent kits.

Examples of preferred tumor antigens of the present invention include tumor-specific proteins such as ErbB receptors, Melan A [MART1], gp100, tyrosinase, TRP-1/gp75, and TRP-2 (in melanoma); MAGE-1 and MAGE-3 (in bladder, head and neck, and non-small cell carcinoma); HPV EG and E7 proteins (in cervical cancer); Mucin [MUC-1] (in breast, pancreas, colon, and prostate cancers); prostate-specific antigen [PSA] (in prostate cancer); carcinoembryonic antigen [CEA] (in colon, breast, and gastrointestinal cancers) and such shared tumor-specific antigens as MAGE-2, MAGE-4, MAGE-6, MAGE-10, MAGE-12, BAGE-1, CAGE-1,2,8, CAGE-3 to 7, LAGE-1, NY-ESO-1/LAGE-2, NA-88, GnTV, and TRP2-INT2. The foregoing list of antigens are intended as exemplary, as the antigen of interest can be derived from any animal or human pathogen or tumor.

In a specific embodiment, the antigen of the invention may be presented by a recombinant virus expressing said antigen. Preferably, the virus is selected from the group consisting of a recombinant adenovirus, recombinant pox virus, and recombinant Sindbis virus.

In the disclosed compositions, both the antigen and the glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant are present in immunogenically effective amounts. For each specific antigen, the optimal immunogenically effective amount should be determined experimentally (taking into consideration specific characteristics of a given patient and/or type of treatment). Generally, this amount is in the range of 0.1 μg-100 mg of an antigen per kg of the body weight. For the glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant of the present invention, the optimal immunogenically effective amount is preferably in the range of 10-100 μg of the adjuvant per kg of the body weight.

The invention also provides a method for preparing a vaccine composition comprising at least one antigen and an adjuvant comprising glycosphingolipids (GSLs) with α-glucose (α-Glc) of Formula 1, said method comprising admixing the adjuvant and the antigen, and optionally one or more physiologically acceptable carriers and/or excipients and/or auxiliary substances.

Formulations and Administration

The invention provides pharmaceutical and vaccine formulations containing therapeutics of the invention (an antigen and glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant either as a single composition or as two separate compositions which can be administered simultaneously or sequentially), which formulations are suitable for administration to elicit an antigen-specific protective immune response for the treatment and prevention of infectious or neoplastic diseases described above. Compositions of the present invention can be formulated in any conventional manner using one or more physiologically acceptable carriers or excipients. Thus, an antigen and/or an adjuvant comprising a glycosphingolipids (GSLs) with α-glucose (α-Glc) of Formula 1, can be formulated for administration by transdermal delivery, or by transmucosal administration, including but not limited to, oral, buccal, intranasal, opthalmic, vaginal, rectal, intracerebral, intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous routes, via scarification (scratching through the top layers of skin, e.g., using a bifurcated needle), by inhalation (pulmonary) or insufflation (either through the mouth or the nose), or by administration to antigen presenting cells ex vivo followed by administration of the cells to the subject, or by any other standard route of immunization.

Preferably, the immunogenic formulations of the invention can be delivered parenterally, i.e., by intravenous (i.v.), subcutaneous (s.c.), intraperitoneal (i.p.), intramuscular (i.m.), subdermal (s.d.), or intradermal (i.d.) administration, by direct injection, via, for example, bolus injection, continuous infusion, or gene gun (e.g., to administer a vector vaccine to a subject, such as naked DNA or RNA). Formulations for injection can be presented in unit dosage form, e.g., in ampoules or in multi-dose containers, with an added preservative. The compositions can take such forms as excipients, suspensions, solutions or emulsions in oily or aqueous vehicles, and can contain formulatory agents such as suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient can be in powder form for reconstitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use.

The present invention also contemplates various mucosal vaccination strategies. While the mucosa can be targeted by local delivery of a vaccine, various strategies have been employed to deliver immunogenic compositions to the mucosa. For example, in a specific embodiment, the immunogenic polypeptide or vector vaccine can be administered in an admixture with, or as a conjugate or chimeric fusion protein with, cholera toxin, such as cholera toxin B or a cholera toxin A/B chimera (see, e.g., Hajishengallis, J Immunol., 154: 4322-32, 1995; Jobling and Holmes, Infect Immun., 60: 4915-24, 1992; Lebens and Holmgren, Dev Biol Stand 82:215-27, 1994). In another embodiment, an admixture with heat labile enterotoxin (LT) can be prepared for mucosal vaccination. Other mucosal immunization strategies include encapsulating the immunogen in microcapsules (see, e.g., U.S. Pat. Nos. 5,075,109; 5,820,883, and 5,853,763) and using an immunopotentiating membranous carrier (see, e.g., PCT Application No. WO 98/0558). Immunogenicity of orally administered immunogens can be enhanced by using red blood cells (rbc) or rbc ghosts (see, e.g., U.S. Pat. No. 5,643,577), or by using blue tongue antigen (see, e.g., U.S. Pat. No. 5,690,938). Systemic administration of a targeted immunogen can also produce mucosal immunization (see, U.S. Pat. No. 5,518,725). Various strategies can be also used to deliver genes for expression in mucosal tissues, such as using chimeric rhinoviruses (see, e.g., U.S. Pat. No. 5,714,374), adenoviruses, vaccinia viruses, or specific targeting of a nucleic acid (see, e.g., PCT Application No. WO 97/05267).

For oral administration, the formulations of the invention can take the form of, for example, tablets or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g., pregelatinized maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g., lactose, microcrystalline cellulose or calcium hydrogen phosphate); lubricants (e.g., magnesium stearate, talc or silica); disintegrants (e.g., potato starch or sodium starch glycolate); or wetting agents (e.g., sodium lauryl sulphate). The tablets can be coated by methods well known in the art. The compositions of the invention can be also introduced in microspheres or microcapsules, e.g., fabricated from poly-glycolic acid/lactic acid (PGLA) (see, U.S. Pat. Nos. 5,814,344; 5,100,669 and 4,849,222; PCT Publication Nos. WO 95/11010 and WO 93/07861). Liquid preparations for oral administration can take the form of, for example, solutions, syrups, emulsions or suspensions, or they can be presented as a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations can be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents (e.g., sorbitol syrup, cellulose derivatives or hydrogenated edible fats); emulsifying agents (e.g., lecithin or acacia); non-aqueous vehicles (e.g., almond oil, oily esters, ethyl alcohol or fractionated vegetable oils); and preservatives (e.g., methyl or propyl-p-hydroxybenzoates or sorbic acid). The preparations can also contain buffer salts, flavoring, coloring and sweetening agents as appropriate. Preparations for oral administration can be suitably formulated to give controlled release of the active compound.

For administration by inhalation, the therapeutics according to the present invention can be conveniently delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use of a suitable propellant, e.g., dichlorodifluoro-methane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurized aerosol the dosage unit can be determined by providing a valve to deliver a metered amount. Capsules and cartridges of, e.g., gelatin for use in an inhaler or insufflator can be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch.

Compositions of the present invention can also be formulated in rectal compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.

In addition to the formulations described previously, the compositions can also be formulated as a depot preparation. Such long acting formulations can be administered by implantation (for example, subcutaneously or intramuscularly) or by intramuscular injection. Thus, for example, the compounds can be formulated with suitable polymeric or hydrophobic materials (for example, as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.

As disclosed herein, an antigen and/or glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant can be mixed with excipients which are pharmaceutically acceptable and compatible with the active ingredients. Suitable excipients are, for example, water, saline, buffered saline, dextrose, glycerol, ethanol, sterile isotonic aqueous buffer or the like and combinations thereof. In addition, if desired, the preparations may also include minor amounts of auxiliary substances such as wetting or emulsifying agents, pH buffering agents, and/or immune stimulators (e.g., adjuvants in addition to glycosphingolipids (GSLs) with α-glucose (α-Glc)) that enhance the effectiveness of the pharmaceutical composition or vaccine. Non-limiting examples of additional immune stimulators which may enhance the effectiveness of the compositions of the present invention include immunostimulatory, immunopotentiating, or pro-inflammatory cytokines, lymphokines, or chemokines or nucleic acids encoding them (specific examples include interleukin (IL)-1, IL-2, IL-3, IL-4, IL-12, IL-13, granulocyte-macrophage (GM)-colony stimulating factor (CSF) and other colony stimulating factors, macrophage inflammatory factor, Flt3 ligand, see additional examples of immunostimulatory cytokines in the Section entitled “Definitions”). These additional immunostimulatory molecules can be delivered systemically or locally as proteins or by expression of a vector that codes for expression of the molecule. The techniques described above for delivery of the antigen and glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant can also be employed for the delivery of additional immunostimulatory molecules.

The invention also provides a pharmaceutical pack or kit comprising one or more containers filled with one or more of the ingredients of the immunogenic formulations of the invention. In a related embodiment, the present invention provides a kit for the preparation of a pharmaceutical or vaccine composition comprising at least one antigen and a glycosphingolipids (GSLs) with α-glucose (α-Glc)-containing adjuvant, said kit comprising the antigen in a first container, and the adjuvant in a second container, and optionally instructions for admixing the antigen and the adjuvant and/or for administration of the composition. Each container of the kit may also optionally include one or more physiologically acceptable carriers and/or excipients and/or auxiliary substances. Associated with such container(s) can be a notice in the form prescribed by a governmental agency regulating the manufacture, use or sale of pharmaceuticals or biological products, which notice reflects approval by the agency of manufacture, use or sale for human administration.

The compositions may, if desired, be presented in a pack or dispenser device which may contain one or more unit dosage forms containing the active ingredient (i.e., an antigen and/or a glycosphingolipids (GSLs) with α-glucose (α-Glc)-containing adjuvant). The pack may, for example, comprise metal or plastic foil, such as a blister pack. The pack or dispenser device may be accompanied by instructions for administration. Compositions of the invention formulated in a compatible pharmaceutical carrier may also be prepared, placed in an appropriate container, and labeled for treatment of an indicated condition.

Effective Dose and Safety Evaluations

According to the methods of the present invention, the pharmaceutical and vaccine compositions described herein are administered to a patient at immunogenically effective doses, preferably, with minimal toxicity. As recited in the Section entitled “Definitions”, “immunogenically effective dose” or “therapeutically effective dose” of disclosed formulations refers to that amount of an antigen and/or glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant that is sufficient to produce an effective immune response in the treated subject and therefore sufficient to result in a healthful benefit to said subject.

Following methodologies which are well-established in the art (see, e.g., reports on evaluation of several vaccine formulations containing novel adjuvants in a collaborative effort between the Center for Biological Evaluation and Food and Drug Administration and the National Institute of Allergy and Infectious Diseases [Goldenthal et al., National Cooperative Vaccine Development Working Group. AIDS Res. Hum. Retroviruses, 1993, 9:545-9]), effective doses and toxicity of the compounds and compositions of the instant invention are first determined in preclinical studies using small animal models (e.g., mice) in which both the antigen and glycosphingolipids (GSLs) with α-glucose (α-Glc)-containing adjuvant has been found to be immunogenic and that can be reproducibly immunized by the same route proposed for the human clinical trials. Specifically, for any pharmaceutical composition or vaccine used in the methods of the invention, the therapeutically effective dose can be estimated initially from animal models to achieve a circulating plasma concentration range that includes the IC₅₀ (i.e., the concentration of the test compound which achieves a half-maximal inhibition of symptoms). Dose-response curves derived from animal systems are then used to determine testing doses for the initial clinical studies in humans. In safety determinations for each composition, the dose and frequency of immunization should meet or exceed those anticipated for use in the clinical trial.

As disclosed herein, the dose of glycosphingolipids (GSLs) with α-glucose (α-Glc), antigen(s) and other components in the compositions of the present invention is determined to ensure that the dose administered continuously or intermittently will not exceed a certain amount in consideration of the results in test animals and the individual conditions of a patient. A specific dose naturally varies depending on the dosage procedure, the conditions of a patient or a subject animal such as age, body weight, sex, sensitivity, feed, dosage period, drugs used in combination, seriousness of the disease. The appropriate dose and dosage times under certain conditions can be determined by the test based on the above-described indices and should be decided according to the judgment of the practitioner and each patient's circumstances according to standard clinical techniques. In this connection, the dose of an antigen is generally in the range of 0.1 μg-100 mg per kg of the body weight, and the dose of the glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant required for augmenting the immune response to the antigen is generally in the range of 10-100 μg per kg of the body weight.

Toxicity and therapeutic efficacy of glycosphingolipids (GSLs) with α-glucose (α-Glc)-containing immunogenic compositions of the invention can be determined by standard pharmaceutical procedures in experimental animals, e.g., by determining the LD₅₀ (the dose lethal to 50% of the population) and the ED₅₀ (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD₅/ED₅₀. Compositions that exhibit large therapeutic indices are preferred. While therapeutics that exhibit toxic side effects can be used (e.g., when treating severe forms of cancer or life-threatening infections), care should be taken to design a delivery system that targets such immunogenic compositions to the specific site (e.g., lymphoid tissue mediating an immune response, tumor or an organ supporting replication of the infectious agent) in order to minimize potential damage to other tissues and organs and, thereby, reduce side effects. As disclosed herein (see also Background Section and Examples), the glycosphingolipids (GSLs) with α-glucose (α-Glc) adjuvant of the invention is not only highly immunostimulating at relatively low doses (e.g., 10-100 μg of the adjuvant per kg of the body weight) but also possesses low toxicity and does not produce significant side effects.

As specified above, the data obtained from the animal studies can be used in formulating a range of dosage for use in humans. The therapeutically effective dosage of glycosphingolipids (GSLs) with α-glucose (α-Glc)-containing compositions of the present invention in humans lies preferably within a range of circulating concentrations that include the ED₅₀ with little or no toxicity. The dosage can vary within this range depending upon the dosage form employed and the route of administration utilized. Ideally, a single dose should be used.

Definitions Directed to Chemical Structures

Definitions of specific functional groups and chemical terms are described in more detail below. The chemical elements are identified in accordance with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75^(th) Ed., inside cover, and specific functional groups are generally defined as described therein. Additionally, general principles of organic chemistry, as well as specific functional moieties and reactivity, are described in Thomas Sorrell, Organic Chemistry, University Science Books, Sausalito, 1999; Smith and March, March's Advanced Organic Chemistry, 5^(th) Edition, John Wiley & Sons, Inc., New York, 2001; Larock, Comprehensive Organic Transformations, VCH Publishers, Inc., New York, 1989; and Carruthers, Some Modern Methods of Organic Synthesis, 3^(rd) Edition, Cambridge University Press, Cambridge, 1987.

Compounds described herein can comprise one or more asymmetric centers, and thus can exist in various isomeric forms, e.g., enantiomers and/or diastereomers. For example, the compounds described herein can be in the form of an individual enantiomer, diastereomer or geometric isomer, or can be in the form of a mixture of stereoisomers, including racemic mixtures and mixtures enriched in one or more stereoisomer. Isomers can be isolated from mixtures by methods known to those skilled in the art, including for example, chiral high pressure liquid chromatography (HPLC) and the formation and crystallization of chiral salts; or preferred isomers can be prepared by asymmetric syntheses. See, for example, Jacques et al., Enantiomers, Racemates and Resolutions (Wiley Interscience, New York, 1981); Wilen et al., Tetrahedron 33:2725 (1977); Eliel, Stereochemistry of Carbon Compounds (McGraw-Hill, N Y, 1962); and Wilen, Tables of Resolving Agents and Optical Resolutions p. 268 (E. L. Eliel, Ed., Univ. of Notre Dame Press, Notre Dame, Ind. 1972). The instant disclosure additionally encompasses compounds described herein as individual isomers substantially free of other isomers, and alternatively, as mixtures of various isomers.

When a range of values is listed, it is intended to encompass each value and sub-range within the range. For example, “C₁₋₆” is intended to encompass C₁, C₂, C₃, C₄, C₅, C₆, C₁₋₆, C₁₋₅, C₁₋₄, C₁₋₃, C₁₋₂, C₂₋₆, C₂₋₅, C₂₋₄, C₂₋₃, C₃₋₆, C₃₋₅, C₃₋₄, C₄₋₆, C₄₋₅, and C₅₋₆.

“Alkyl” refers to a radical of a straight-chain or branched saturated hydrocarbon group having from 1 to 20 carbon atoms (“C₁₋₂₀ alkyl”). In some embodiments, an alkyl group has 1 to 10 carbon atoms (“C₁₋₁₀ alkyl”). In some embodiments, an alkyl group has 1 to 9 carbon atoms (“C₁₋₉ alkyl”). In some embodiments, an alkyl group has 1 to 8 carbon atoms (“C₁₋₈ alkyl”). In some embodiments, an alkyl group has 1 to 7 carbon atoms (“C₁₋₇ alkyl”). In some embodiments, an alkyl group has 1 to 6 carbon atoms (“C₁₋₆ alkyl”). In some embodiments, an alkyl group has 1 to 5 carbon atoms (“C₁₋₅ alkyl”). In some embodiments, an alkyl group has 1 to 4 carbon atoms (“C₁₋₄ alkyl”). In some embodiments, an alkyl group has 1 to 3 carbon atoms (“C₁₋₃ alkyl”). In some embodiments, an alkyl group has 1 to 2 carbon atoms (“C₁₋₂ alkyl”). In some embodiments, an alkyl group has 1 carbon atom (“C₁ alkyl”). In some embodiments, an alkyl group has 2 to 6 carbon atoms (“C₂₋₆ alkyl”). Examples of C₁₋₆ alkyl groups include methyl (C₁), ethyl (C₂), n-propyl (C₃), iso-propyl (C₃), n-butyl (C₄), tert-butyl (C₄), sec-butyl (C₄), isobutyl (C₄), n-pentyl (C₅), 3-pentanyl (C₅), amyl (C₅), neopentyl (C₅), 3-methyl-2-butanyl (C₅), tertiary amyl (C₅), and n-hexyl (C₆). Additional examples of alkyl groups include n-heptyl (C₇), n-octyl (C₈) and the like. Unless otherwise specified, each instance of an alkyl group is independently optionally substituted, i.e., unsubstituted (an “unsubstituted alkyl”) or substituted (a “substituted alkyl”) with one or more substituents. In certain embodiments, the alkyl group is unsubstituted C₁₋₁₀ alkyl (e.g., —CH₃). In certain embodiments, the alkyl group is substituted C₁₋₁₀ alkyl.

“Alkenyl” refers to a radical of a straight-chain or branched hydrocarbon group having from 2 to 20 carbon atoms, one or more carbon-carbon double bonds, and no triple bonds (“C₂₋₂₀ alkenyl”). In some embodiments, an alkenyl group has 2 to 10 carbon atoms (“C₂₋₁₀ alkenyl”). In some embodiments, an alkenyl group has 2 to 9 carbon atoms (“C₂₋₉ alkenyl”). In some embodiments, an alkenyl group has 2 to 8 carbon atoms (“C₂₋₈ alkenyl”). In some embodiments, an alkenyl group has 2 to 7 carbon atoms (“C₂₋₇ alkenyl”). In some embodiments, an alkenyl group has 2 to 6 carbon atoms (“C₂₋₆ alkenyl”). In some embodiments, an alkenyl group has 2 to 5 carbon atoms (“C₂₋₅ alkenyl”). In some embodiments, an alkenyl group has 2 to 4 carbon atoms (“C₂₋₄ alkenyl”). In some embodiments, an alkenyl group has 2 to 3 carbon atoms (“C₂₋₃ alkenyl”). In some embodiments, an alkenyl group has 2 carbon atoms (“C₂ alkenyl”). The one or more carbon-carbon double bonds can be internal (such as in 2-butenyl) or terminal (such as in 1-butenyl). Examples of C₂₋₄ alkenyl groups include ethenyl (C₂), 1-propenyl (C₃), 2-propenyl (C₃), 1-butenyl (C₄), 2-butenyl (C₄), butadienyl (C₄), and the like. Examples of C₂₋₆ alkenyl groups include the aforementioned C₂₋₄ alkenyl groups as well as pentenyl (C₅), pentadienyl (C₅), hexenyl (C₆), and the like. Additional examples of alkenyl include heptenyl (C₇), octenyl (C₈), octatrienyl (C₈), and the like. Unless otherwise specified, each instance of an alkenyl group is independently optionally substituted, i.e., unsubstituted (an “unsubstituted alkenyl”) or substituted (a “substituted alkenyl”) with one or more substituents. In certain embodiments, the alkenyl group is unsubstituted C₂₋₁₀ alkenyl. In certain embodiments, the alkenyl group is substituted C₂₋₁₀ alkenyl.

“Alkynyl” refers to a radical of a straight-chain or branched hydrocarbon group having from 2 to 20 carbon atoms, one or more carbon-carbon triple bonds, and optionally one or more double bonds (“C₂₋₂₀ alkynyl”). In some embodiments, an alkynyl group has 2 to 10 carbon atoms (“C₂₋₁₀ alkynyl”). In some embodiments, an alkynyl group has 2 to 9 carbon atoms (“C₂₋₉ alkynyl”). In some embodiments, an alkynyl group has 2 to 8 carbon atoms (“C₂₋₈ alkynyl”). In some embodiments, an alkynyl group has 2 to 7 carbon atoms (“C₂₋₇ alkynyl”). In some embodiments, an alkynyl group has 2 to 6 carbon atoms (“C₂₋₆ alkynyl”). In some embodiments, an alkynyl group has 2 to 5 carbon atoms (“C₂₋₅ alkynyl”). In some embodiments, an alkynyl group has 2 to 4 carbon atoms (“C₂₋₄ alkynyl”). In some embodiments, an alkynyl group has 2 to 3 carbon atoms (“C₂₋₃ alkynyl”). In some embodiments, an alkynyl group has 2 carbon atoms (“C2 alkynyl”). The one or more carbon-carbon triple bonds can be internal (such as in 2-butynyl) or terminal (such as in 1-butynyl). Examples of C₂₋₄ alkynyl groups include, without limitation, ethynyl (C₂), 1-propynyl (C₃), 2-propynyl (C₃), 1-butynyl (C₄), 2-butynyl (C₄), and the like. Examples of C₂₋₆ alkenyl groups include the aforementioned C₂₋₄ alkynyl groups as well as pentynyl (C₅), hexynyl (C₆), and the like. Additional examples of alkynyl include heptynyl (C₇), octynyl (C₈), and the like. Unless otherwise specified, each instance of an alkynyl group is independently optionally substituted, i.e., unsubstituted (an “unsubstituted alkynyl”) or substituted (a “substituted alkynyl”) with one or more substituents. In certain embodiments, the alkynyl group is unsubstituted C₂₋₁₀ alkynyl. In certain embodiments, the alkynyl group is substituted C₂₋₁₀ alkynyl.

“Carbocyclyl” or “carbocyclic” refers to a radical of a non-aromatic cyclic hydrocarbon group having from 3 to 10 ring carbon atoms (“C₃₋₁₀ carbocyclyl”) and zero heteroatoms in the non-aromatic ring system. In some embodiments, a carbocyclyl group has 3 to 8 ring carbon atoms (“C₃₋₈ carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 6 ring carbon atoms (“C₃₋₆ carbocyclyl”). In some embodiments, a carbocyclyl group has 3 to 6 ring carbon atoms (“C₃₋₆ carbocyclyl”). In some embodiments, a carbocyclyl group has 5 to 10 ring carbon atoms (“C₅₋₁₀ carbocyclyl”). Exemplary C₃₋₆ carbocyclyl groups include, without limitation, cyclopropyl (C₃), cyclopropenyl (C₃), cyclobutyl (C₄), cyclobutenyl (C₄), cyclopentyl (C₅), cyclopentenyl (C₅), cyclohexyl (C₆), cyclohexenyl (C₆), cyclohexadienyl (C₆), and the like. Exemplary C₃₋₈ carbocyclyl groups include, without limitation, the aforementioned C₃₋₆ carbocyclyl groups as well as cycloheptyl (C₇), cycloheptenyl (C₇), cycloheptadienyl (C₇), cycloheptatrienyl (C₇), cyclooctyl (C₈), cyclooctenyl (C₈), 40ydroxy[2.2.1]heptanyl (C₇), 40ydroxy[2.2.2]octanyl (C₈), and the like. Exemplary C₃₋₁₀ carbocyclyl groups include, without limitation, the aforementioned C₃₋₈ carbocyclyl groups as well as cyclononyl (C₉), cyclononenyl (C₉), cyclodecyl (C₁₀), cyclodecenyl (C₁₀), octahydro-1H-indenyl (C₉), decahydronaphthalenyl (C₁₀), spiro[4.5]decanyl (C₁₀), and the like. As the foregoing examples illustrate, in certain embodiments, the carbocyclyl group is either monocyclic (“monocyclic carbocyclyl”) or contain a fused, bridged or spiro ring system such as a bicyclic system (“bicyclic carbocyclyl”) and can be saturated or can be partially unsaturated. “Carbocyclyl” also includes ring systems wherein the carbocyclic ring, as defined above, is fused to one or more aryl or heteroaryl groups wherein the point of attachment is on the carbocyclic ring, and in such instances, the number of carbons continue to designate the number of carbons in the carbocyclic ring system. Unless otherwise specified, each instance of a carbocyclyl group is independently optionally substituted, i.e., unsubstituted (an “unsubstituted carbocyclyl”) or substituted (a “substituted carbocyclyl”) with one or more substituents. In certain embodiments, the carbocyclyl group is unsubstituted C₃₋₁₀ carbocyclyl. In certain embodiments, the carbocyclyl group is a substituted C₃₋₁₀ carbocyclyl.

In some embodiments, “carbocyclyl” is a monocyclic, saturated carbocyclyl group having from 3 to 10 ring carbon atoms (“C₃₋₁₀ cycloalkyl”). In some embodiments, a cycloalkyl group has 3 to 8 ring carbon atoms (“C₃₋₈ cycloalkyl”). In some embodiments, a cycloalkyl group has 3 to 6 ring carbon atoms (“C₃₋₆ cycloalkyl”). In some embodiments, a cycloalkyl group has 5 to 6 ring carbon atoms (“C₅₋₆ cycloalkyl”). In some embodiments, a cycloalkyl group has 5 to 10 ring carbon atoms (“C₅₋₁₀ cycloalkyl”). Examples of C₅₋₆ cycloalkyl groups include cyclopentyl (C₅) and cyclohexyl (C₅). Examples of C₃₋₆ cycloalkyl groups include the aforementioned C₅₋₆ cycloalkyl groups as well as cyclopropyl (C₃) and cyclobutyl (C₄). Examples of C₃₋₈ cycloalkyl groups include the aforementioned C₃₋₆ cycloalkyl groups as well as cycloheptyl (C₇) and cyclooctyl (C₈). Unless otherwise specified, each instance of a cycloalkyl group is independently unsubstituted (an “unsubstituted cycloalkyl”) or substituted (a “substituted cycloalkyl”) with one or more substituents. In certain embodiments, the cycloalkyl group is unsubstituted C₃₋₁₀ cycloalkyl. In certain embodiments, the cycloalkyl group is substituted C₃₋₁₀ cycloalkyl.

“Heterocyclyl” or “heterocyclic” refers to a radical of a 3- to 10-membered non-aromatic ring system having ring carbon atoms and 1 to 4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, sulfur, boron, phosphorus, and silicon (“3-10 membered heterocyclyl”). In certain embodiments, the heteroatom is independently selected from nitrogen, sulfur, and oxygen. In heterocyclyl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. A heterocyclyl group can either be monocyclic (“monocyclic heterocyclyl”) or a fused, bridged or spiro ring system such as a bicyclic system (“bicyclic heterocyclyl”), and can be saturated or partially unsaturated. Heterocyclyl bicyclic ring systems can include one or more heteroatoms in one or both rings. “Heterocyclyl” also includes ring systems wherein the heterocyclic ring, as defined above, is fused with one or more carbocyclyl groups wherein the point of attachment is either on the carbocyclyl or heterocyclic ring, or ring systems wherein the heterocyclic ring, as defined above, is fused with one or more aryl or heteroaryl groups, wherein the point of attachment is on the heterocyclic ring, and in such instances, the number of ring members continue to designate the number of ring members in the heterocyclic ring system. Unless otherwise specified, each instance of heterocyclyl is independently optionally substituted, i.e., unsubstituted (an “unsubstituted heterocyclyl”) or substituted (a “substituted heterocyclyl”) with one or more substituents. In certain embodiments, the heterocyclyl group is unsubstituted 3-10 membered heterocyclyl. In certain embodiments, the heterocyclyl group is substituted 3-10 membered heterocyclyl.

In some embodiments, a heterocyclyl group is a 5-10 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, sulfur, boron, phosphorus, and silicon (“5-10 membered heterocyclyl”). In some embodiments, a heterocyclyl group is a 5-8 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-8 membered heterocyclyl”). In some embodiments, a heterocyclyl group is a 5-6 membered non-aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-6 membered heterocyclyl”). In some embodiments, the 5-6 membered heterocyclyl has 1-3 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heterocyclyl has 1-2 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heterocyclyl has one ring heteroatom selected from nitrogen, oxygen, and sulfur.

Exemplary 3-membered heterocyclyl groups containing one heteroatom include, without limitation, azirdinyl, oxiranyl, and thiorenyl. Exemplary 4-membered heterocyclyl groups containing one heteroatom include, without limitation, azetidinyl, oxetanyl, and thietanyl. Exemplary 5-membered heterocyclyl groups containing one heteroatom include, without limitation, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothiophenyl, dihydrothiophenyl, pyrrolidinyl, dihydropyrrolyl, and pyrrolyl-2,5-dione. Exemplary 5-membered heterocyclyl groups containing two heteroatoms include, without limitation, dioxolanyl, oxasulfuranyl, disulfuranyl, and oxazolidin-2-one. Exemplary 5-membered heterocyclyl groups containing three heteroatoms include, without limitation, triazolinyl, oxadiazolinyl, and thiadiazolinyl. Exemplary 6-membered heterocyclyl groups containing one heteroatom include, without limitation, piperidinyl, tetrahydropyranyl, dihydropyridinyl, and thianyl. Exemplary 6-membered heterocyclyl groups containing two heteroatoms include, without limitation, piperazinyl, morpholinyl, dithianyl, and dioxanyl. Exemplary 6-membered heterocyclyl groups containing two heteroatoms include, without limitation, triazinanyl. Exemplary 7-membered heterocyclyl groups containing one heteroatom include, without limitation, azepanyl, oxepanyl, and thiepanyl. Exemplary 8-membered heterocyclyl groups containing one heteroatom include, without limitation, azocanyl, oxecanyl, and thiocanyl. Exemplary 5-membered heterocyclyl groups fused to a C₆ aryl ring (also referred to herein as a 5,6-bicyclic heterocyclic ring) include, without limitation, indolinyl, isoindolinyl, dihydrobenzofuranyl, dihydrobenzothienyl, benzoxazolinonyl, and the like. Exemplary 6-membered heterocyclyl groups fused to an aryl ring (also referred to herein as a 6,6-bicyclic heterocyclic ring) include, without limitation, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and the like.

“Aryl” refers to a radical of a monocyclic or polycyclic (e.g., bicyclic or tricyclic) 4n+2 aromatic ring system (e.g., having 6, 10, or 14 π electrons shared in a cyclic array) having 6-14 ring carbon atoms and zero heteroatoms in the aromatic ring system (“C₆₋₁₄ aryl”). In some embodiments, an aryl group has six ring carbon atoms (“C₆ aryl”; e.g., phenyl). In some embodiments, an aryl group has ten ring carbon atoms (“C₁₀ aryl”; e.g., naphthyl such as 1-naphthyl and 2-naphthyl). In some embodiments, an aryl group has fourteen ring carbon atoms (“C₁₄ aryl”; e.g., anthracyl). “Aryl” also includes ring systems wherein the aryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the radical or point of attachment is on the aryl ring, and in such instances, the number of carbon atoms continue to designate the number of carbon atoms in the aryl ring system. Unless otherwise specified, each instance of an aryl group is independently optionally substituted, i.e., unsubstituted (an “unsubstituted aryl”) or substituted (a “substituted aryl”) with one or more substituents. In certain embodiments, the aryl group is unsubstituted C₆₋₁₄ aryl. In certain embodiments, the aryl group is substituted C₆₋₁₄ aryl.

“Arylalkyl” is a subset of alkyl and aryl, as defined herein, and refers to an optionally substituted alkyl group substituted by an optionally substituted aryl group. In certain embodiments, the aralkyl is optionally substituted benzyl. In certain embodiments, the aralkyl is benzyl. In certain embodiments, the aralkyl is optionally substituted phenethyl. In certain embodiments, the aralkyl is phenethyl.

“Heteroaryl” refers to a radical of a 5-10 membered monocyclic or bicyclic 4n+2 aromatic ring system (e.g., having 6 or 10 π electrons shared in a cyclic array) having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-10 membered heteroaryl”). In heteroaryl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. Heteroaryl bicyclic ring systems can include one or more heteroatoms in one or both rings. “Heteroaryl” includes ring systems wherein the heteroaryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the point of attachment is on the heteroaryl ring, and in such instances, the number of ring members continue to designate the number of ring members in the heteroaryl ring system. “Heteroaryl” also includes ring systems wherein the heteroaryl ring, as defined above, is fused with one or more aryl groups wherein the point of attachment is either on the aryl or heteroaryl ring, and in such instances, the number of ring members designates the number of ring members in the fused (aryl/heteroaryl) ring system. Bicyclic heteroaryl groups wherein one ring does not contain a heteroatom (e.g., indolyl, quinolinyl, carbazolyl, and the like) the point of attachment can be on either ring, i.e., either the ring bearing a heteroatom (e.g., 2-indolyl) or the ring that does not contain a heteroatom (e.g., 5-indolyl).

In some embodiments, a heteroaryl group is a 5-10 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-10 membered heteroaryl”). In some embodiments, a heteroaryl group is a 5-8 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-8 membered heteroaryl”). In some embodiments, a heteroaryl group is a 5-6 membered aromatic ring system having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur (“5-6 membered heteroaryl”). In some embodiments, the 5-6 membered heteroaryl has 1-3 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heteroaryl has 1-2 ring heteroatoms selected from nitrogen, oxygen, and sulfur. In some embodiments, the 5-6 membered heteroaryl has 1 ring heteroatom selected from nitrogen, oxygen, and sulfur. Unless otherwise specified, each instance of a heteroaryl group is independently optionally substituted, i.e., unsubstituted (an “unsubstituted heteroaryl”) or substituted (a “substituted heteroaryl”) with one or more substituents. In certain embodiments, the heteroaryl group is unsubstituted 5-14 membered heteroaryl. In certain embodiments, the heteroaryl group is substituted 5-14 membered heteroaryl.

Exemplary 5-membered heteroaryl groups containing one heteroatom include, without limitation, pyrrolyl, furanyl and thiophenyl. Exemplary 5-membered heteroaryl groups containing two heteroatoms include, without limitation, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, and isothiazolyl. Exemplary 5-membered heteroaryl groups containing three heteroatoms include, without limitation, triazolyl, oxadiazolyl, and thiadiazolyl. Exemplary 5-membered heteroaryl groups containing four heteroatoms include, without limitation, tetrazolyl. Exemplary 6-membered heteroaryl groups containing one heteroatom include, without limitation, pyridinyl. Exemplary 6-membered heteroaryl groups containing two heteroatoms include, without limitation, pyridazinyl, pyrimidinyl, and pyrazinyl. Exemplary 6-membered heteroaryl groups containing three or four heteroatoms include, without limitation, triazinyl and tetrazinyl, respectively. Exemplary 7-membered heteroaryl groups containing one heteroatom include, without limitation, azepinyl, oxepinyl, and thiepinyl. Exemplary 5,6-bicyclic heteroaryl groups include, without limitation, indolyl, isoindolyl, indazolyl, benzotriazolyl, benzothiophenyl, isobenzothiophenyl, benzofuranyl, benzoisofuranyl, benzimidazolyl, benzoxazolyl, benzisoxazolyl, benzoxadiazolyl, benzthiazolyl, benzisothiazolyl, benzthiadiazolyl, indolizinyl, and purinyl. Exemplary 6,6-bicyclic heteroaryl groups include, without limitation, naphthyridinyl, pteridinyl, quinolinyl, isoquinolinyl, cinnolinyl, quinoxalinyl, phthalazinyl, and quinazolinyl.

“Heteroaralkyl” is a subset of alkyl and heteroaryl, as defined herein, and refers to an optionally substituted alkyl group substituted by an optionally substituted heteroaryl group.

Alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl groups, as defined herein, which are divalent bridging groups are further referred to using the suffix -ene, e.g., alkylene, alkenylene, alkynylene, carbocyclylene, heterocyclylene, arylene, and heteroarylene.

As used herein, the term “optionally substituted” refers to a substituted or unsubstituted moiety.

Alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl groups, as defined herein, are optionally substituted (e.g., “substituted” or “unsubstituted” alkyl, “substituted” or “unsubstituted” alkenyl, “substituted” or “unsubstituted” alkynyl, “substituted” or “unsubstituted” carbocyclyl, “substituted” or “unsubstituted” heterocyclyl, “substituted” or “unsubstituted” aryl or “substituted” or “unsubstituted” heteroaryl group). In general, the term “substituted”, whether preceded by the term “optionally” or not, means that at least one hydrogen present on a group (e.g., a carbon or nitrogen atom) is replaced with a permissible substituent, e.g., a substituent which upon substitution results in a stable compound, e.g., a compound which does not spontaneously undergo transformation such as by rearrangement, cyclization, elimination, or other reaction. Unless otherwise indicated, a “substituted” group has a substituent at one or more substitutable positions of the group, and when more than one position in any given structure is substituted, the substituent is either the same or different at each position. The term “substituted” is contemplated to include substitution with all permissible substituents of organic compounds, any of the substituents described herein that results in the formation of a stable compound. The present invention contemplates any and all such combinations in order to arrive at a stable compound. For purposes of this invention, heteroatoms such as nitrogen may have hydrogen substituents and/or any suitable substituent as described herein which satisfy the valencies of the heteroatoms and results in the formation of a stable moiety.

Exemplary carbon atom substituents include, but are not limited to, halogen, —CN, —NO₂, —N₃, —SO₂H, —SO₃H, —OH, —OR^(aa), —ON(R^(bb))₂, —N(R^(bb))₂, —N(R^(bb))₃ ⁺X⁻, —N(OR^(cc))R^(bb), —SH, —SR^(aa), —SSR^(cc), —C(═O)R^(aa), —CO₂H, —CHO, —C(OR^(cc))₂, —CO₂R^(aa), —OC(═O)R^(aa), —OCO₂R^(aa), —C(═O)N(R^(bb))₂, —OC(═O)N(R^(bb))₂, —NR^(bb)C(═O)R^(aa), —NR^(bb)CO₂R^(aa), —NR^(bb)C(═O)N(R^(bb))₂, —C(═NR^(bb))R^(aa), —C(═NR^(bb))OR^(aa), —OC(═NR^(bb))R^(aa), —OC(═NR^(bb))OR^(aa), —C(═NR^(bb))N(R^(bb))₂, —OC(═NR^(bb))N(R^(bb))₂, —NR^(bb)C(═NR^(bb))N(R^(bb))₂, —C(═O)NR^(bb)SO₂R^(aa), —NR^(bb)SO₂R^(aa), —SO₂N(R^(bb))₂, —SO₂R^(aa), —SO₂OR^(aa), —OSO₂R^(aa), —S(═O)R^(aa), —OS(═O)R^(aa), —Si(R^(aa))₃, —Osi(R^(aa))₃, —C(═S)N(R^(bb))₂, —C(═O)SR^(aa), —C(═S)SR^(aa), —SC(═S)SR^(aa), —SC(═O)SR^(aa), —OC(═O)SR^(aa), —SC(═O)OR^(aa), —SC(═O)R^(aa), —P(═O)₂R^(aa), —OP(═O)₂R^(aa), —P(═O)(R^(aa))₂, —OP(═O)(R^(aa))₂, —OP(═O)(OR^(cc))₂, —P(═O)₂N(R^(bb))₂, —OP(═O)₂N(R^(bb))₂, —P(═O)(NR^(bb))₂, —OP(═O)(NR^(bb))₂, —NR^(bb)P(═O)(OR^(cc))₂, —NR^(bb)P(═O)(NR^(bb))₂, —P(R^(cc))₂, —P(R^(cc))₃, —OP(R^(cc))₂, —OP(R^(cc))₃, —B(R^(aa))₂, —B(OR^(cc))₂, —BR^(aa)(OR^(cc)), C₁₋₁₀ alkyl, C₁₋₁₀ perhaloalkyl, C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, C₃₋₁₀ carbocyclyl, 3-14 membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 R^(dd) groups; or two hydrogens on a carbon atom are replaced with the group ═O, ═S, ═NN(R^(bb))₂, ═NNR^(bb)C(═O)R^(aa), ═NNR^(bb)C(═O)OR^(aa), ═NNR^(bb)S(═O)₂R^(aa), ═NR^(bb), or ═NOR^(cc); each instance of R^(aa) is, independently, selected from C₁₋₁₀ alkyl, C₁₋₁₀ perhaloalkyl, C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, C₃₋₁₀ carbocyclyl, 3-14 membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl, or two R^(aa) groups are joined to form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 R^(dd) groups; each instance of R^(bb) is, independently, selected from hydrogen, —OH, —OR^(aa), —N(R^(cc))₂, —CN, —C(═O)R^(aa), —C(═O)N(R^(cc))₂, —CO₂R^(aa), —SO₂R^(aa), —C(═NR^(cc))OR^(aa), —C(═NR^(cc))N(R^(cc))₂, —SO₂N(R^(cc))₂, —SO₂R^(cc), —SO₂OR^(cc), —SOR^(aa), —C(═S)N(R^(cc))₂, —C(═O)SR^(cc), —C(═S)SR^(cc), —P(═O)₂R^(aa), —P(═O)(R^(aa))₂, —P(═O)₂N(R^(cc))₂, —P(═O)(NR^(cc))₂, C₁₋₁₀ alkyl, C₁₋₁₀ perhaloalkyl, C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, C₃₋₁₀ carbocyclyl, 3-14 membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl, or two R^(bb) groups are joined to form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 R^(dd) groups; each instance of R^(cc) is, independently, selected from hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ perhaloalkyl, C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, C₃₋₁₀ carbocyclyl, 3-14 membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl, or two R^(cc) groups are joined to form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 R^(dd) groups; each instance of R^(dd) is, independently, selected from halogen, —CN, —NO₂, —N₃, —SO₂H, —SO₃H, —OH, —OR^(ee), —ON(R^(ff))₂, —N(R^(ff))₂, —N(R^(ff))₃ ⁺X⁻, —N(OR^(ee))R^(ff), —SH, —SR^(ee), —SSR^(ee), —C(═O)R^(ee), —CO₂H, —CO₂R^(ee), —OC(═O)R^(ee), —OCO₂R^(ee), —C(═O)N(R^(ff))₂, —OC(═O)N(R^(ff))₂, —NR^(ff)C(═O)R^(ee), —NR^(ff)CO₂R^(ee), —NR^(ff)C(═O)N(R^(ff))₂, —C(═NR^(ff))OR^(ee), —OC(═NR^(ff))R^(ee), —OC(═NR^(ff))OR^(ee), —C(═NR^(ff))N(R^(ff))₂, —OC(═NR^(ff))N(R^(ff))₂, —NR^(ff)C(═NR^(ff))N(R^(ff))₂, —NR^(ff)SO₂R^(ee), —SO₂N(R^(ff))₂, —SO₂R^(ee), —SO₂OR^(ee), —OSO₂R^(ee), —S(═O)R^(ee), —Si(R^(ee))₃, —Osi(R^(ee))₃, —C(═S)N(R^(ff))₂, —C(═O)SR^(ee), —C(═S)SR^(ee), —SC(═S)SR^(ee), —P(═O)₂R^(ee), —P(═O)(R^(ee))₂, —OP(═O)(R^(ee))₂, —OP(═O)(OR^(ee))₂, C₁₋₆ alkyl, C₁₋₆ perhaloalkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₁₀ carbocyclyl, 3-10 membered heterocyclyl, C₆₋₁₀ aryl, 5-10 membered heteroaryl, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 R^(gg) groups, or two R^(dd) substituents can be joined to form ═O or ═S; each instance of R^(ee) is, independently, selected from C₁₋₆ alkyl, C₁₋₆ perhaloalkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₁₀ carbocyclyl, C₆₋₁₀ aryl, 3-10 membered heterocyclyl, and 3-10 membered heteroaryl, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 R^(gg) groups; each instance of R^(ff) is, independently, selected from hydrogen, C₁₋₆ alkyl, C₁₋₆ perhaloalkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₁₀ carbocyclyl, 3-10 membered heterocyclyl, C₆₋₁₀ aryl and 5-10 membered heteroaryl, or two R^(ff) groups are joined to form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 R^(gg) groups; and each instance of R^(gg) is, independently, halogen, —CN, —NO₂, —N₃, —SO₂H, —SO₃H, —OH, —OC₁₋₆ alkyl, —ON(C₁₋₆ alkyl)₂, —N(C₁₋₆ alkyl)₂, —N(C₁₋₆ alkyl)₃ ⁺X⁻, —NH(C₁₋₆ alkyl)₂ ⁺X⁻, —NH₂(C₁₋₆ alkyl)⁺X⁻, —NH₃ ⁺X⁻, —N(OC₁₋₆ alkyl)(C₁₋₆ alkyl), —N(OH)(C₁₋₆ alkyl), —NH(OH), —SH, —SC₁₋₆ alkyl, —SS(C₁₋₆ alkyl), —C(═O)(C₁₋₆ alkyl), —CO₂H, —CO₂(C₁₋₆ alkyl), —OC(═O)(C₁₋₆ alkyl), —OCO₂(C₁₋₆ alkyl), —C(═O)NH₂, —C(═O)N(C₁₋₆ alkyl)₂, —OC(═O)NH(C₁₋₆ alkyl), —NHC(═O)(C₁₋₆ alkyl), —N(C₁₋₆ alkyl)C(═O)(C₁₋₆ alkyl), —NHCO₂(C₁₋₆ alkyl), —NHC(═O)N(C₁₋₆ alkyl)₂, —NHC(═O)NH(C₁₋₆ alkyl), —NHC(═O)NH₂, —C(═NH)O(C₁₋₆ alkyl), —OC(═NH)(C₁₋₆ alkyl), —OC(═NH)OC₁₋₆ alkyl, —C(═NH)N(C₁₋₆ alkyl)₂, —C(═NH)NH(C₁₋₆ alkyl), —C(═NH)NH₂, —OC(═NH)N(C₁₋₆ alkyl)₂, —OC(NH)NH(C₁₋₆ alkyl), —OC(NH)NH₂, —NHC(NH)N(C₁₋₆ alkyl)₂, —NHC(═NH)NH₂, —NHSO₂(C₁₋₆ alkyl), —SO₂N(C₁₋₆ alkyl)₂, —SO₂NH(C₁₋₆ alkyl), —SO₂NH₂, —SO₂C₁₋₆ alkyl, —SO₂OC₁₋₆ alkyl, —OSO₂C₁₋₆ alkyl, —SOC₁₋₆ alkyl, —Si(C₁₋₆ alkyl)₃, —Osi(C₁₋₆ alkyl)₃, —C(═S)N(C₁₋₆ alkyl)₂, C(═S)NH(C₁₋₆ alkyl), C(═S)NH₂, —C(═O)S(C₁₋₆ alkyl), —C(═S)SC₁₋₆ alkyl, —SC(═S)SC₁₋₆ alkyl, —P(═O)₂(C₁₋₆ alkyl), —P(═O)(C₁₋₆ alkyl)₂, —OP(═O)(C₁₋₆ alkyl)₂, —OP(═O)(OC₁₋₆ alkyl)₂, C₁₋₆ alkyl, C₁₋₆ perhaloalkyl, C₂₋₆ alkenyl, C₂₋₆ alkynyl, C₃₋₁₀ carbocyclyl, C₆₋₁₀ aryl, 3-10 membered heterocyclyl, 5-10 membered heteroaryl; or two R^(gg) substituents can be joined to form ═O or ═S; wherein X⁻ is a counterion.

“Halo” or “halogen” refers to fluorine (fluoro, —F), chlorine (chloro, —Cl), bromine (bromo, —Br), or iodine (iodo, —I).

“Acyl” as used herein refers to a moiety selected from the group consisting of —C(═O)R^(aa), —CHO, —CO₂R^(aa), —C(═O)N(R^(bb))₂, —C(═NR^(bb))R^(aa), —C(═NR^(bb))OR^(aa), —C(═NR^(bb))N(R^(bb))₂, —C(═O)NR^(bb)SO₂R^(aa), —C(═S)N(R^(bb))₂, —C(═O)SR^(aa), and —C(═S)SR^(aa), wherein R^(a)a and R^(bb) are as defined herein.

Nitrogen atoms can be substituted or unsubstituted as valency permits, and include primary, secondary, tertiary, and quarternary nitrogen atoms. Exemplary nitrogen atom substituents include, but are not limited to, hydrogen, —OH, —OR^(aa), —N(R^(cc))₂, —CN, —C(═O)R^(aa), —C(═O)N(R^(aa))₂, —CO₂R^(aa), —SO₂R^(aa), —C(═NR^(bb))R^(aa), —C(═NR^(cc))OR^(aa), —C(═NR^(cc))N(R^(cc))₂, —SO₂N(R^(cc))₂, —SO₂R^(cc), —SO₂OR^(cc), —SOR^(aa), —C(═S)N(R^(cc))₂, —C(═O)SR^(cc), —C(═S)SR^(cc), —P(═O)₂R^(aa), —P(═O)(R^(aa))₂, —P(═O)₂N(R^(cc))₂, —P(═O)(NR^(cc))₂, C₁₋₁₀ alkyl, C₁₋₁₀ perhaloalkyl, C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, C₃₋₁₀ carbocyclyl, 3-14 membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl, or two R^(cc) groups attached to a nitrogen atom are joined to form a 3-14 membered heterocyclyl or 5-14 membered heteroaryl ring, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 R^(dd) groups, and wherein R^(aa), R^(bb), R^(cc), and R^(dd) are as defined above.

In certain embodiments, the substituent present on a nitrogen atom is a nitrogen protecting group (also referred to as an amino protecting group). Nitrogen protecting groups include, but are not limited to, —OH, —OR^(aa), —N(R^(cc))₂, —C(═O)R^(aa), —C(═O)N(R^(cc))₂, —CO₂R^(aa), —SO₂R^(aa), —C(═NR^(cc))R^(aa), —C(═NR^(cc))OR^(aa), —C(═NR^(cc))N(R^(cc))₂, —SO₂N(R^(cc))₂, —SO₂R^(cc), —SO₂OR^(cc), —SOR^(aa), —C(═S)N(R^(cc))₂, —C(═O)SR^(cc), —C(═S)SR^(cc), C₁₋₁₀ alkyl (e.g., aralkyl, heteroaralkyl), C₂₋₁₀ alkenyl, C₂₋₁₀ alkynyl, C₃₋₁₀ carbocyclyl, 3-14 membered heterocyclyl, C₆₋₁₄ aryl, and 5-14 membered heteroaryl groups, wherein each alkyl, alkenyl, alkynyl, carbocyclyl, heterocyclyl, aralkyl, aryl, and heteroaryl is independently substituted with 0, 1, 2, 3, 4, or 5 R^(dd) groups, and wherein R^(aa), R^(bb), R^(cc) and R^(dd) are as defined herein. Nitrogen protecting groups are well known in the art and include those described in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3^(rd) edition, John Wiley & Sons, 1999, incorporated herein by reference.

For example, nitrogen protecting groups such as amide groups (e.g., —C(═O)R^(aa)) include, but are not limited to, formamide, acetamide, chloroacetamide, trichloroacetamide, trifluoroacetamide, phenylacetamide, 3-phenylpropanamide, picolinamide, 3-pyridylcarboxamide, N-benzoylphenylalanyl derivative, benzamide, p-phenylbenzamide, o-nitophenylacetamide, o-nitrophenoxyacetamide, acetoacetamide, (N′ dithiobenzyloxyacylamino)acetamide, 3-(p-hydroxyphenyl)propanamide, 3-(o-nitrophenyl)propanamide, 2-methyl-2-(o-nitrophenoxy)propanamide, 2-methyl-2-(o-phenylazophenoxy)propanamide, 4-chlorobutanamide, 3-methyl-3-nitrobutanamide, o-nitrocinnamide, N-acetylmethionine derivative, o-nitrobenzamide, and o-(benzoyloxymethyl)benzamide.

Nitrogen protecting groups such as carbamate groups (e.g., —C(═O)OR^(aa)) include, but are not limited to, methyl carbamate, ethyl carbamante, 9-fluorenylmethyl carbamate (Fmoc), 9-(2-sulfo)fluorenylmethyl carbamate, 9-(2,7-dibromo)fluoroenylmethyl carbamate, 2,7-di-t-butyl-[9-(10,10-dioxo-10,10,10,10-tetrahydrothioxanthyl)]methyl carbamate (DBD-Tmoc), 4-methoxyphenacyl carbamate (Phenoc), 2,2,2-trichloroethyl carbamate (Troc), 2-trimethylsilylethyl carbamate (Teoc), 2-phenylethyl carbamate (hZ), 1-(1-Adamantyl)-1-methylethyl (Adpoc), 1,1-dimethyl-2-haloethyl carbamate, 1,1-dimethyl-2,2-dibromoethyl carbamate (DB-t-BOC), 1,1-dimethyl-2,2,2-trichloroethyl carbamate (TCBOC), 1-methyl-1-(4-biphenylyl)ethyl carbamate (Bpoc), 1-(3,5-di-t-butylphenyl)-1-methylethyl carbamate (t Bumeoc), 2-(2′- and 4′-pyridyl)ethyl carbamate (Pyoc), 2-(N,N-dicyclohexylcarboxamido)ethyl carbamate, t-butyl carbamate (BOC), 1-adamantyl carbamate (Adoc), vinyl carbamate (Voc), allyl carbamate (Alloc), 1-isopropylallyl carbamate (Ipaoc), cinnamyl carbamate (Coc), 4-nitrocinnamyl carbamate (Noc), 8-quinolyl carbamate, N-hydroxypiperidinyl carbamate, alkyldithio carbamate, benzyl carbamate (Cbz), p-methoxybenzyl carbamate (Moz), p-nitobenzyl carbamate, p-bromobenzyl carbamate, p-chlorobenzyl carbamate, 2,4-dichlorobenzyl carbamate, 4-methylsulfinylbenzyl carbamate (Msz), 9-anthrylmethyl carbamate, diphenylmethyl carbamate, 2-methylthioethyl carbamate, 2-methylsulfonylethyl carbamate, 2-(p-toluenesulfonyl)ethyl carbamate, [2-(1,3-dithianyl)]methyl carbamate (Dmoc), 4-methylthiophenyl carbamate (Mtpc), 2,4-dimethylthiophenyl carbamate (Bmpc), 2-phosphonioethyl carbamate (Peoc), 2-triphenylphosphonioisopropyl carbamate (Ppoc), 1,1-dimethyl-2-cyanoethyl carbamate, m-chloro-p-acyloxybenzyl carbamate, p-(dihydroxyboryl)benzyl carbamate, 5-benzisoxazolylmethyl carbamate, 2-(trifluoromethyl)-6-chromonylmethyl carbamate (Tcroc), m-nitrophenyl carbamate, 3,5-dimethoxybenzyl carbamate, o-nitrobenzyl carbamate, 3,4-dimethoxy-6-nitrobenzyl carbamate, phenyl(o-nitrophenyl)methyl carbamate, t-amyl carbamate, S-benzyl thiocarbamate, p-cyanobenzyl carbamate, cyclobutyl carbamate, cyclohexyl carbamate, cyclopentyl carbamate, cyclopropylmethyl carbamate, p-decyloxybenzyl carbamate, 2,2-dimethoxyacylvinyl carbamate, o-(N,N-dimethylcarboxamido)benzyl carbamate, 1,1-dimethyl-3-(N,N-dimethylcarboxamido)propyl carbamate, 1,1-dimethylpropynyl carbamate, di(2-pyridyl)methyl carbamate, 2-furanylmethyl carbamate, 2-iodoethyl carbamate, isoborynl carbamate, isobutyl carbamate, isonicotinyl carbamate, p-(p′-methoxyphenylazo)benzyl carbamate, 1-methylcyclobutyl carbamate, 1-methylcyclohexyl carbamate, 1-methyl-1-cyclopropylmethyl carbamate, 1-methyl-1-(3,5-dimethoxyphenyl)ethyl carbamate, 1-methyl-1-(p-phenylazophenyl)ethyl carbamate, 1-methyl-1-phenylethyl carbamate, 1-methyl-1-(4-pyridyl)ethyl carbamate, phenyl carbamate, p-(phenylazo)benzyl carbamate, 2,4,6-tri-t-butylphenyl carbamate, 4-(trimethylammonium)benzyl carbamate, and 2,4,6-trimethylbenzyl carbamate.

Nitrogen protecting groups such as sulfonamide groups (e.g., —S(═O)₂R^(aa)) include, but are not limited to, p-toluenesulfonamide (Ts), benzenesulfonamide, 2,3,6-trimethyl-4-methoxybenzenesulfonamide (Mtr), 2,4,6-trimethoxybenzenesulfonamide (Mtb), 2,6-dimethyl-4-methoxybenzenesulfonamide (Pme), 2,3,5,6-tetramethyl-4-methoxybenzenesulfonamide (Mte), 4-methoxybenzenesulfonamide (Mbs), 2,4,6-trimethylbenzenesulfonamide (Mts), 2,6-dimethoxy-4-methylbenzenesulfonamide (iMds), 2,2,5,7,8-pentamethylchroman-6-sulfonamide (Pmc), methanesulfonamide (Ms), β-trimethyl silylethanesulfonamide (SES), 9-anthracenesulfonamide, 4-(4′,8′-dimethoxynaphthylmethyl)benzenesulfonamide (DNMBS), benzylsulfonamide, trifluoromethylsulfonamide, and phenacylsulfonamide.

Other nitrogen protecting groups include, but are not limited to, phenothiazinyl-(10)-acyl derivative, N′-p-toluenesulfonylaminoacyl derivative, N′-phenylaminothioacyl derivative, N-benzoylphenylalanyl derivative, N-acetylmethionine derivative, 4,5-diphenyl-3-oxazolin-2-one, N-phthalimide, N-dithiasuccinimide (Dts), N-2,3-diphenylmaleimide, N-2,5-dimethylpyrrole, N-1,1,4,4-tetramethyldisilylazacyclopentane adduct (STABASE), 5-substituted 1,3-dimethyl-1,3,5-triazacyclohexan-2-one, 5-substituted 1,3-dibenzyl-1,3,5-triazacyclohexan-2-one, 1-substituted 3,5-dinitro-4-hydroxyl, N-methylamine, N-allylamine, N-[2-(trimethylsilyl)ethoxy]methylamine (SEM), N-3-acetoxypropylamine, N-(1-isopropyl-4-nitro-2-oxo-3-pyroolin-3-yl)amine, quaternary ammonium salts, N-benzylamine, N-di(4-methoxyphenyl)methylamine, N-5-dibenzosuberylamine, N-triphenylmethylamine (Tr), N-[(4-methoxyphenyl)diphenylmethyl]amine (MMTr), N-9-phenylfluorenylamine (PhF), N-2,7-dichloro-9-fluorenylmethyleneamine, N-ferrocenylmethylamino (Fcm), N-2-picolylamino N′-oxide, N-1,1-dimethylthiomethyleneamine, N-benzylideneamine, N-p-methoxybenzylideneamine, N-diphenylmethyleneamine, N-[(2-pyridyl)mesityl]methyleneamine, N—(N′,N′-dimethylaminomethylene)amine, N,N′-isopropylidenediamine, N-p-nitrobenzylideneamine, N-salicylideneamine, N-5-chlorosalicylideneamine, N-(5-chloro-2-hydroxyphenyl)phenylmethyleneamine, N-cyclohexylideneamine, N-(5,5-dimethyl-3-oxo-1-cyclohexenyl)amine, N-borane derivative, N-diphenylborinic acid derivative, N-[phenyl(pentaacylchromium- or tungsten)acyl]amine, N-copper chelate, N-zinc chelate, N-nitroamine, N-nitrosoamine, amine N-oxide, diphenylphosphinamide (Dpp), dimethylthiophosphinamide (Mpt), diphenylthiophosphinamide (Ppt), dialkyl phosphoramidates, dibenzyl phosphoramidate, diphenyl phosphoramidate, benzenesulfenamide, o-nitrobenzenesulfenamide (Nps), 2,4-dinitrobenzenesulfenamide, pentachlorobenzenesulfenamide, 2-nitro-4-methoxybenzenesulfenamide, triphenylmethylsulfenamide, and 3-nitropyridinesulfenamide (Npys).

In certain embodiments, the substituent present on an oxygen atom is an oxygen protecting group (also referred to as a hydroxyl protecting group). Oxygen protecting groups include, but are not limited to, —R^(aa), —N(R^(bb))₂, —C(═O)SR^(aa), —C(═O)R^(aa), —CO₂R^(aa), —C(═O)N(R^(bb))₂, —C(═NR^(bb))R^(aa), —C(═NR^(bb))OR^(aa), —C(═NR^(bb))N(R^(bb))₂, —S(═O)R^(aa), —SO₂R^(aa), —Si(R^(aa))₃, —P(R^(cc))₂, —P(R^(cc))₃, —P(═O)₂R^(aa), —P(═O)(R^(aa))₂, —P(═O)(OR^(cc))₂, —P(═O)₂N(R^(bb))₂, and —P(═O)(NR^(bb))₂, wherein R^(aa), R^(bb), and R^(cc) are as defined herein. Oxygen protecting groups are well known in the art and include those described in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3^(rd) edition, John Wiley & Sons, 1999, incorporated herein by reference.

Exemplary oxygen protecting groups include, but are not limited to, methyl, methoxylmethyl (MOM), methylthiomethyl (MTM), t-butylthiomethyl, (phenyldimethylsilyl)methoxymethyl (SMOM), benzyloxymethyl (BOM), p-methoxybenzyloxymethyl (PMBM), (4-methoxyphenoxy)methyl (p-AOM), guaiacolmethyl (GUM), t-butoxymethyl, 4-pentenyloxymethyl (POM), siloxymethyl, 2-methoxyethoxymethyl (MEM), 2,2,2-trichloroethoxymethyl, bis(2-chloroethoxy)methyl, 2-(trimethyl silyl)ethoxymethyl (SEMOR), tetrahydropyranyl (THP), 3-bromotetrahydropyranyl, tetrahydrothiopyranyl, 1-methoxycyclohexyl, 4-methoxytetrahydropyranyl (MTHP), 4-methoxytetrahydrothiopyranyl, 4-methoxytetrahydrothiopyranyl S,S-dioxide, 1-[(2-chloro-4-methyl)phenyl]-4-methoxypiperidin-4-yl (CTMP), 1,4-dioxan-2-yl, tetrahydrofuranyl, tetrahydrothiofuranyl, 2,3,3a,4,5,6,7,7a-octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl, 1-ethoxyethyl, 1-(2-chloroethoxy)ethyl, 1-methyl-1-methoxyethyl, 1-methyl-1-benzyloxyethyl, 1-methyl-1-benzyloxy-2-fluoroethyl, 2,2,2-trichloroethyl, 2-trimethyl silylethyl, 2-(phenylselenyl)ethyl, t-butyl, allyl, p-chlorophenyl, p-methoxyphenyl, 2,4-dinitrophenyl, benzyl (Bn), p-methoxybenzyl, 3,4-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, p-halobenzyl, 2,6-dichlorobenzyl, p-cyanobenzyl, p-phenylbenzyl, 2-picolyl, 4-picolyl, 3-methyl-2-picolyl N-oxido, diphenylmethyl, p,p′-dinitrobenzhydryl, 5-dibenzosuberyl, triphenylmethyl, α-naphthyldiphenylmethyl, p-methoxyphenyldiphenylmethyl, di(p-methoxyphenyl)phenylmethyl, tri(p-methoxyphenyl)methyl, 4-(4′-bromophenacyloxyphenyl)diphenylmethyl, 4,4′,4″-tris(4,5-dichlorophthalimidophenyl)methyl, 4,4′,4″-tris(levulinoyloxyphenyl)methyl, 4,4′,4″-tris(benzoyloxyphenyl)methyl, 3-(imidazol-1-yl)bis(4′,4″-dimethoxyphenyl)methyl, 1,1-bis(4-methoxyphenyl)-1′-pyrenylmethyl, 9-anthryl, 9-(9-phenyl)xanthenyl, 9-(9-phenyl-10-oxo)anthryl, 1,3-benzodithiolan-2-yl, benzisothiazolyl S,S-dioxido, trimethylsilyl (TMS), triethylsilyl (TES), triisopropylsilyl (TIPS), dimethylisopropylsilyl (IPDMS), diethylisopropylsilyl (DEIPS), dimethylthexylsilyl, t-butyldimethylsilyl (TBDMS), t-butyldiphenylsilyl (TBDPS), tribenzylsilyl, tri-p-xylylsilyl, triphenylsilyl, diphenylmethylsilyl (DPMS), t-butylmethoxyphenylsilyl (TBMPS), formate, benzoylformate, acetate, chloroacetate, dichloroacetate, trichloroacetate, trifluoroacetate, methoxyacetate, triphenylmethoxyacetate, phenoxyacetate, p-chlorophenoxyacetate, 3-phenylpropionate, 4-oxopentanoate (levulinate), 4,4-(ethylenedithio)pentanoate (levulinoyldithioacetal), pivaloate, adamantoate, crotonate, 4-methoxycrotonate, benzoate, p-phenylbenzoate, 2,4,6-trimethylbenzoate (mesitoate), methyl carbonate, 9-fluorenylmethyl carbonate (Fmoc), ethyl carbonate, 2,2,2-trichloroethyl carbonate (Troc), 2-(trimethylsilyl)ethyl carbonate (TMSEC), 2-(phenylsulfonyl) ethyl carbonate (Psec), 2-(triphenylphosphonio) ethyl carbonate (Peoc), isobutyl carbonate, vinyl carbonate, allyl carbonate, t-butyl carbonate (BOC), p-nitrophenyl carbonate, benzyl carbonate, p-methoxybenzyl carbonate, 3,4-dimethoxybenzyl carbonate, o-nitrobenzyl carbonate, p-nitrobenzyl carbonate, S-benzyl thiocarbonate, 4-ethoxy-1-napththyl carbonate, methyl dithiocarbonate, 2-iodobenzoate, 4-azidobutyrate, 4-nitro-4-methylpentanoate, o-(dibromomethyl)benzoate, 2-formylbenzenesulfonate, 2-(methylthiomethoxy)ethyl, 4-(methylthiomethoxy)butyrate, 2-(methylthiomethoxymethyl)benzoate, 2,6-dichloro-4-methylphenoxyacetate, 2,6-dichloro-4-(1,1,3,3-tetramethylbutyl)phenoxyacetate, 2,4-bis(1,1-dimethylpropyl)phenoxyacetate, chlorodiphenylacetate, isobutyrate, monosuccinoate, (E)-2-methyl-2-butenoate, o-(methoxyacyl)benzoate, α-naphthoate, nitrate, alkyl N,N,N′,N′-tetramethylphosphorodiamidate, alkyl N-phenylcarbamate, borate, dimethylphosphinothioyl, alkyl 2,4-dinitrophenylsulfenate, sulfate, methanesulfonate (mesylate), benzylsulfonate, and tosylate (Ts).

In certain embodiments, the substituent present on a sulfur atom is a sulfur protecting group (also referred to as a thiol protecting group). Sulfur protecting groups include, but are not limited to, —R^(aa), —N(R^(bb))₂, —C(═O)SR^(aa), —C(═O)R^(aa), —CO₂R^(aa), —C(═O)N(R^(bb))₂, —C(═NR^(bb))R^(aa), —C(═NR^(bb))OR^(aa), —C(═NR^(bb))N(R^(bb))₂, —S(═O)R^(aa), —SO₂R^(aa), —Si(R^(aa))₃, —P(R^(cc))₂, —P(R^(cc))₃, —P(═O)₂R^(aa), —P(═O)(R^(aa))₂, —P(═O)(OR^(cc))₂, —P(═O)₂N(R^(bb))₂, and —P(═O)(NR^(bb))₂, wherein R^(aa), R^(bb), and R^(cc) are as defined herein. Sulfur protecting groups are well known in the art and include those described in Protecting Groups in Organic Synthesis, T. W. Greene and P. G. M. Wuts, 3^(rd) edition, John Wiley & Sons, 1999, incorporated herein by reference.

As used herein, the term “leaving group” is given its ordinary meaning in the art of synthetic organic chemistry and refers to an atom or a group capable of being displaced by a nucleophile. Examples of suitable leaving groups include, but are not limited to, halogen (such as F, Cl, Br, or I (iodine)), alkoxycarbonyloxy, aryloxycarbonyloxy, alkanesulfonyloxy, arenesulfonyloxy, alkyl-carbonyloxy (e.g., acetoxy), arylcarbonyloxy, aryloxy, methoxy, N,O-dimethylhydroxylamino, pixyl, and haloformates. In some cases, the leaving group is a sulfonic acid ester, such as toluenesulfonate (tosylate, —OTs), methanesulfonate (mesylate, —OMs), p-bromobenzenesulfonyloxy (brosylate, —OBs), or trifluoromethanesulfonate (triflate, —OTf). In some cases, the leaving group is a brosylate, such as p-bromobenzenesulfonyloxy. In some cases, the leaving group is a nosylate, such as 2-nitrobenzenesulfonyloxy. In some embodiments, the leaving group is a sulfonate-containing group. In some embodiments, the leaving group is a tosylate group. The leaving group may also be a phosphineoxide (e.g., formed during a Mitsunobu reaction) or an internal leaving group such as an epoxide or cyclic sulfate. Other non-limiting examples of leaving groups are water, ammonia, alcohols, ether moieties, thioether moieties, zinc halides, magnesium moieties, diazonium salts, and copper moieties.

Exemplary α-GalCer analogs (GSLs with α-Glc) are used as immunologic adjuvants to accelerate, enhance, prolong, and/or modify or augment the effects of a vaccine by stimulating the immune system of a patient who has been vaccinated. In an exemplary implementation, the analog C34 is used as an adjuvant. As used herein, the term “alum adjuvant” refers to an aluminum salt with immune adjuvant activity, such as, for example, aluminum phosphate and aluminum hydroxide. These exemplary agents can adsorb and precipitates protein antigens in solution; the resulting precipitate improves vaccine immunogenicity by facilitating the slow release of antigen from the vaccine depot formed at the site of inoculation. Additionally, adjuvants contemplated herein can also include suitable organic adjuvants and suitable virosomes. In certain embodiments, exemplary organic adjuvants can include oil-based adjuvants such as squalene, MF59, QS-21 and AS03.

As used herein, the term “anti-tumor immunotherapy active agent” refers to antibody generated by a vaccine of the present disclosure that inhibits, reduces and/or eliminates tumors, either alone and/or in combination with other synergistic agents.

Glycosphingolipids (GSLs) bearing α-galactosyl group (αGal) and phenyl ring on the acyl chain were known to be more potent than α-galactosyl ceramide (αGalCer) to stimulate both murine and human invariant NKT (iNKT) cells. Their activities in mice and humans correlated with the binding avidities of the ternary interaction between iNKT TCR and CD1d-GSL complex.

The instant disclosure relates to the unexpected discovery that GSLs with glucose (αGlc) are stronger than those with αGal for humans but weaker for mice in the induction of cytokines/chemokines and expansion/activation of immune cells. GSLs with glucose (αGlc) and F derivatives of αGlc, and their impact on their immunostimulatory activities in humans are disclosed herein. The immune-stimulatory potencies associated with the strength of ternary interaction for each species are described herein. It is the iNKT TCR rather than CD1d that dictates the species-specific responses, as demonstrated by mCD1d vs. hCD1d swapping assay disclosed herein. Glycosphingolipids (GSLs) with αGlc bear stronger ternary interaction and triggered more Th1-biased immunity as compared to GSLs with αGal in humans. GSLs with αGlc are less stimulatory than GSLs with αGal in mice. The species-specific responses are attributed to the differential binding avidities of ternary complexes between species, reflecting the differences between murine and human iNKT TCR as supported by mCD1d vs. hCD1d swapping assay as described herein.

These novel findings indicate differences in species and provide novel designs of GSL with modifications on the glycosyl group that are more effective for human therapy.

Compounds

The instant disclosure relates to exemplary immune adjuvant compounds of Formula (I):

or pharmaceutically acceptable salt thereof; wherein R¹ is —OH or halogen; R² is —OH, hydrogen or halogen; R³ is hydrogen or halogen; R⁴ and R⁵ are each independently selected from the group consisting of hydrogen, halogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted aryl, optionally substituted heterocyclyl, optionally substituted heteroaryl, optionally substituted alkoxy, an optionally substituted amino group, or optionally substituted acyl; n is an integer of 1 to 15, inclusive; and m is an integer of 1 to 20, inclusive.

In some embodiments of compound (I), R² is —OH. In some embodiments of compound (I), R² is hydrogen. In some embodiments of compound (I), R² is halogen. In some embodiments of compound (I), R² is F. In some embodiments of compound (I), R² is Cl. In some embodiments of compound (I), R² is Br. In some embodiments of compound (I), R² is I.

In some embodiments of compound (I), R¹ is —OH. In some embodiments of compound (I), R¹ is halogen. In some embodiments of compound (I), R¹ is F. In some embodiments of compound (I), R¹ is Cl. In some embodiments of compound (I), R¹ is Br. In some embodiments of compound (I), R¹ is I.

In some embodiments of compound (I), R³ is hydrogen. In some embodiments of compound (I), R³ is halogen. In some embodiments of compound (I), R³ is F. In some embodiments of compound (I), R³ is Cl. In some embodiments of compound (I), R³ is Br. In some embodiments of compound (I), R³ is I.

In some embodiments of compound (I), R¹ is —OH; R² is —OH, hydrogen or halogen; and R³ is hydrogen or halogen. In some embodiments of compound (I), R¹ is —OH; R² is —OH; and R³ is hydrogen or halogen. In some embodiments of compound (I), R¹ is —OH; R² is hydrogen; and R³ is hydrogen or halogen. In some embodiments of compound (I), R¹ is —OH; R² is halogen; and R³ is hydrogen or halogen. In some embodiments of compound (I), R¹ is halogen; R² is —OH, hydrogen or halogen; and R³ is hydrogen or halogen. In some embodiments of compound (I), R¹ is halogen; R² is —OH; and R³ is hydrogen or halogen. In some embodiments of compound (I), R¹ is halogen; R² is hydrogen; and R³ is hydrogen or halogen. In some embodiments of compound (I), R¹ is halogen; R² is halogen; and R³ is hydrogen or halogen.

In some embodiments of compound (I), R⁴ is phenyl. In some embodiments, R⁴ is optionally substituted phenyl of Formula (II):

wherein i=0, 1, 2, 3, 4, or 5; each instance of R⁶ is independently selected from the group consisting of hydrogen, halogen, —CN, —NO₂, —N₃, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted phenyl, optionally substituted heterocyclyl, optionally substituted heteroaryl, optionally substituted alkoxy, an optionally substituted amino group, or optionally substituted acyl. In certain embodiments, i is 0. In certain embodiments, i is 1. In certain embodiments, i is 2. In certain embodiments, i is 3. In certain embodiments, i is 4. In certain embodiments, i is 5. In certain embodiments, i is 1 and R⁶ is halogen. In certain embodiments, i is 1 and R⁴ is one of the formulae:

In certain embodiments, i is 2 and R⁴ is one of the formulae:

In certain embodiments, i is 3 and R⁴ is one of the formulae:

In certain embodiments, i is 4 and R⁴ is one of the formulae:

In certain embodiments, i is 5 and R⁴ is of the formula

In some embodiments of compound (I), R⁶ is halogen. In some embodiments of compound (I), R⁶ is F. In some embodiments of compound (I), R⁶ is Cl. In some embodiments of compound (I), R⁶ is Br. In some embodiments of compound (I), R⁶ is I.

In some embodiments of compound (I), R⁴ is optionally substituted aryl. In some embodiments of compound (I), R⁴ is of Formula (III):

wherein j is 0, 1, 2, 3, or 4; k is 0, 1, 2, 3, 4, or 5; each instance of R⁷ and R⁸ is independently selected from the group consisting of hydrogen, halogen, —CN, —NO₂, —N₃, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted phenyl, optionally substituted heterocyclyl, optionally substituted heteroaryl, optionally substituted alkoxy, an optionally substituted amino group, or optionally substituted acyl. In certain embodiments, k is 0. In certain embodiments, k is 1. In certain embodiments, k is 2. In certain embodiments, k is 3. In certain embodiments, k is 4. In certain embodiments, k is 5. In certain embodiments, k is 1 and R⁸ is halogen. In certain embodiments, k is 1 and R⁴ is one of the formulae:

In certain embodiments, k is 2 and R⁴ is one of the formulae:

In certain embodiments, k is 3 and R⁴ is one of the formulae:

In certain embodiments, k is 4 and R⁴ is one of the formulae:

In certain embodiments, k is 5 and R⁴ is of the formula

In some embodiments of compound (I), n is an integer of 1 to 15, inclusive. In some embodiments of compound (I), n is an integer of 5 to 15, inclusive. In some embodiments of compound (I), n is an integer of 10 to 15, inclusive. In some embodiments of compound (I), n is 10. In some embodiments of compound (I), n is 11. In some embodiments of compound (I), n is 12. In some embodiments of compound (I), n is 13. In some embodiments of compound (I), n is 14. In some embodiments of compound (I), n is 15.

In some embodiments of compound (I), m is an integer of 1 to 20, inclusive. In some embodiments of compound (I), m is an integer of 5 to 20, inclusive. In some embodiments of compound (I), m is an integer of 5 to 15, inclusive. In some embodiments of compound (I), m is an integer of 10 to 15, inclusive. In some embodiments of compound (I), m is 10. In some embodiments of compound (I), m is 11. In some embodiments of compound (I), m is 12. In some embodiments of compound (I), m is 13. In some embodiments of compound (I), m is 14. In some embodiments of compound (I), m is 15.

The In some embodiments of compound (I), R⁷ is hydrogen; R⁸ is F; and k is 1, 2 or 3. In some embodiments of compound (I), R⁷ is F; R⁸ is a hydrogen; and j is 1, 2 or 3. In some embodiments of compound (I), R⁷ and R⁸ both are F; k is 1, 2 or 3; and j is 1, 2 or 3.

In some embodiments of formula (I), the provided compound is one of the following compounds:

Pharmaceutical Compositions

The present disclosure provides pharmaceutical compositions comprising an exemplary compound described herein and a pharmaceutically acceptable excipient. The compositions disclosed herein can be included in a pharmaceutical or nutraceutical composition together with additional active agents, carriers, vehicles, excipients, or auxiliary agents identifiable by a person skilled in the art upon reading of the present disclosure.

The pharmaceutical compositions preferably comprise at least one pharmaceutically acceptable carrier. In such pharmaceutical compositions, the compositions disclosed herein form the “active compound,” also referred to as the “active agent.” As used herein the language “pharmaceutically acceptable carrier” includes solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. Supplementary active compounds can also be incorporated into the compositions. A pharmaceutical composition is formulated to be compatible with its intended route of administration. Examples of routes of administration include parenteral, e.g., intravenous, intradermal, subcutaneous, oral (e.g., inhalation), transdermal (topical), transmucosal, and rectal administration. Solutions or suspensions used for parenteral, intradermal, or subcutaneous application can include the following components: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol, or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates, or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. The parenteral preparation can be enclosed in ampoules, disposable syringes, or multiple dose vials made of glass or plastic.

Subject as used herein refers to humans and non-human primates (e.g., guerilla, macaque, marmoset), livestock animals (e.g., sheep, cow, horse, donkey, and pig), companion animals (e.g., dog, cat), laboratory test animals (e.g., mouse, rabbit, rat, guinea pig, hamster), captive wild animals (e.g., fox, deer), and any other organisms who can benefit from the agents of the present disclosure. There is no limitation on the type of animal that could benefit from the presently described agents. A subject regardless of whether it is a human or non-human organism may be referred to as a patient, individual, animal, host, or recipient.

Pharmaceutical compositions suitable for an injectable use include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, Cremophor EL™ (BASF, Parsippany, N.J.), or phosphate buffered saline (PBS). In all cases, the composition should be sterile and should be fluid to the extent that easy syringability exists. It should be stable under the conditions of manufacture and storage and be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols such as manitol, sorbitol, or sodium chloride in the composition. Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate and gelatin.

Uses of Compositions Described Herein

The present invention provides compositions useful for stimulating an immune response in a human subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of a composition disclosed herein.

The compositions described herein can also be used to elevate invariant Natural Killer T (iNKT) cells production in a human subject in need thereof, the method comprising: administering to the subject in need thereof a therapeutically effective amount of a pharmaceutically acceptable composition, wherein the composition comprises an exemplary compound disclosed herein.

The exemplary compositions described herein can also be used to stimulate cytokine and/or chemokine production in a human subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of a pharmaceutically acceptable composition, wherein the composition comprises an amount sufficient to increase cytokine/chemokine production, of a compound disclosed herein.

By an “effective” amount or a “therapeutically effective” amount of an active agent is meant a nontoxic but sufficient amount of the agent to provide a beneficial effect. The amount of active agent that is “effective” will vary from subject to subject, depending on the age and general condition of the individual, the particular active agent or agents, and the like. Unless otherwise indicated, the term “therapeutically effective” amount as used herein is intended to encompass an amount effective for the prevention of an adverse condition and/or the amelioration of an adverse condition, i.e., in addition to an amount effective for the treatment of an adverse condition.

As defined herein, a therapeutically effective amount of the active compound (i.e., an effective dosage) may range from about 0.001 to 100 g/kg body weight, or other ranges that would be apparent and understood by artisans without undue experimentation. The skilled artisan will appreciate that certain factors can influence the dosage and timing required to effectively treat a subject, including but not limited to the severity of the disease or disorder, previous treatments, the general health or age of the subject, and other diseases present.

An adverse condition as that term is used herein may be a “normal” condition that is frequently seen in individuals or a pathologic condition that may or may not be associated with a named disease.

As used herein, the term “lipid” refers to any fat-soluble (lipophilic) molecule that participates in cell signaling pathways.

As used herein, the term “glycolipid” refers to a carbohydrate-attached lipid that serves as a marker for cellular recognition.

According to another aspect, one or more kits of parts can be envisioned by the person skilled in the art, the kits of parts to perform at least one of the methods herein disclosed, the kit of parts comprising two or more compositions, the compositions comprising alone or in combination an effective amount of the compositions disclosed herein according to the at least one of the above mentioned methods.

The kits possibly include also compositions comprising active agents, identifiers of a biological event, or other compounds identifiable by a person skilled upon reading of the present disclosure. The kit can also comprise at least one composition comprising an effective amount of the compositions disclosed herein or a cell line. The compositions and the cell line of the kits of parts to be used to perform the at least one method herein disclosed according to procedure identifiable by a person skilled in the art.

As used herein, the term “specifically binding,” refers to the interaction between binding pairs (e.g., an antibody and an antigen). In various instances, specifically binding can be embodied by an affinity constant of about 10⁻⁶ moles/liter, about 10⁻⁷ moles/liter, or about 10⁻⁸ moles/liter, or less.

As will be apparent to those of skill in the art upon reading this invention, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present invention. Any recited method can be carried out in the order of events recited or in any other order that is logically possible.

In one aspect, the immune composition described herein can be administered parenterally (e.g., intravenous injection, subcutaneous injection or intramuscular injection). Alternatively, other modes of administration including suppositories and oral formulations may be desirable. For suppositories, binders and carriers may include, for example, polyalkalene glycols or triglycerides. Oral formulations may include normally employed incipients such as, for example, pharmaceutical grades of saccharine, cellulose, magnesium carbonate and the like. These compositions take the form of solutions, suspensions, tablets, pills, capsules, sustained release formulations or powders and contain 10-95% of the immune composition described herein.

The immune composition is administered in a manner compatible with the dosage formulation, and in an amount that is therapeutically effective, protective and immunogenic. The quantity to be administered depends on the subject to be treated, including, for example, the capacity of the individual's immune system to synthesize antibodies, and if needed, to produce a cell-mediated immune response. Precise amounts of active ingredient required to be administered depend on the judgment of the practitioner. However, suitable dosage ranges are readily determinable by one skilled in the art. Suitable regimes for initial administration and booster doses are also variable, but may include an initial administration followed by subsequent administrations. The dosage of the vaccine may also depend on the route of administration and varies according to the size of the host.

The immune composition of this invention can also be used to generate antibodies in animals for production of antibodies, which can be used in both cancer treatment and diagnosis. Methods of making monoclonal and polyclonal antibodies and fragments thereof in animals (e.g., mouse, rabbit, goat, sheep, or horse) are well known in the art. See, for example, Harlow and Lane, (1988) Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, New York. The term “antibody” includes intact immunoglobulin molecules as well as fragments thereof, such as Fab, F(ab′)₂, Fv, scFv (single chain antibody), and dAb (domain antibody; Ward, et. al. (1989) Nature, 341, 544).

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the case of conflict, the present document, including definitions will control. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications and patents specifically mentioned herein are incorporated by reference for all purposes including describing and disclosing the chemicals, cell lines, vectors, animals, instruments, statistical analysis and methodologies which are reported in the publications which might be used in connection with the invention. All references cited in this specification are to be taken as indicative of the level of skill in the art. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.

Before the present materials and methods are described, it is understood that this invention is not limited to the particular methodology, protocols, materials, and reagents described, as these may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included

EXAMPLES

The following examples are put forth so as to provide those skilled in the art with a complete invention and description of how to make and use embodiments in accordance with the invention, and are not intended to limit the scope of what the inventors regard as their discovery. Efforts have been made to ensure accuracy with respect to numbers used (e.g. amounts, temperature, etc.) but some experimental errors and deviations should be accounted for.

Unless indicated otherwise, parts are parts by weight, molecular weight is weight average molecular weight, temperature is in degrees Centigrade, and pressure is at or near atmospheric.

General:

All reagent chemicals were purchased as reagent grade and used without further purification. Anhydrous solvents such as dichloromethane (CH₂Cl₂), tetrahydrofuran (THF), N,N-dimethylformamide (DMF), methanol (MeOH), pyridine were purchased from Acros. HPLC grade solvents chloroform (CHCl₃) and methanol were purchased from Merck. Molecular sieves 4 Å (MS 4 Å) for glycosylation was purchased from Acros and activated by flame. Reactions were monitored with analytical thin layer chromatography (TLC) in EM silica gel 60 F254 plates and visualized under UV (254 nm) and/or staining with acidic ceric ammonium molybdate or ninhydrin. Flash column chromatography was performed on silica gel 60 Geduran (40-63 m, Merck). Biogel LH20 for purification of final products was purchased from Aldrich. ¹H NMR spectra were recorded on a Bruker Topspin-600 (600 MHz) spectrometer at 20° C. Chemical shifts (6 ppm) were assigned according to the internal standard signal of CDCl₃ (δ=7.24 ppm), MeOD (δ=3.31 ppm), and pyridine-d⁵ (δ=7.58 ppm). ¹³C NMR spectra were obtained on a Bruker Topspin-600 (150 MHz) spectrometer and were reported in 6 ppm scale using the signal of CDCl₃ (δ=77.23 ppm), MeOD (δ=49.15 ppm) for calibration. Coupling constants (J) are reported in Hz. Splitting patterns are described by using the following abbreviations: s, singlet; d, doublet; t, triplet; dd, double doublet; m, multiplet. ¹H NMR spectra are reported in this order: chemical shift; multiplicity; number(s) of proton; coupling constant(s).

Chemical Syntheses

Synthesis of Glucosyl Donor 8

Compound 2:

To a solution of 1,2,3,4,6-Penta-O-acetyl-β-D-glucopyranose 1 (40 g, 102.5 mmol) in 200 mL of dry CH₂Cl₂ was added p-toluenethiol (15.4 g, 123 mmol) and BF₃OEt₂ (15.4 mL, 123 mmol) at 0° C., the reaction was stirred for 16 h at ambient temperature under argon. The resulting solution was directly extracted with saturated NaHCO₃ solution and brine, dried over MgSO₄ and evaporated. Followed by recrystallization in a solution of AcOEt-hexanes to give 2 as white solid (32.6 g, 70%). #H NMR (CDCl₃, 600 MHz) δ 7.36 (2H, d, J=7.2 Hz), 7.10 (2H, d, J=7.8 Hz), 5.18 (1H, t, J=9.0 Hz), 5.00 (1H, t, J=9.6 Hz), 4.91 (1H, t, J=9.0 Hz), 4.61 (1H, d, J=10.2 Hz), 4.14-4.20 (2H, m), 3.67 (1H, s), 2.33 (3H, s), 2.07 (3H, s), 2.06 (3H, s,), 1.99 (3H, s), 1.96 (3H, s). ¹³C NMR (CDCl₃, 150 MHz) δ 170.78, 170.40, 169.59, 169.45, 139.00, 134.04, 129.88, 127.73, 86.03, 75.94, 74.21, 70.10, 68.38, 62.32, 21.39, 20.97, 20.94, 20.79, 20.78. HRMS (ESI-TOF) for C₂₁H₂₆O₉SNa⁺ [M+Na]⁺ calcd 477.1190, found 477.1201.

Compound 3:

To a solution of 2 (32.6 g, 71.8 mmol) in 500 mL of dry MeOH was added catalytic amount of sodium methoxide (NaOMe) and stirred for 3 h at ambient temperature. The reaction was neutralized by adding Amberlite IR-120 and filtered, the resulting solution was concentrated to dryness to give 3 (20.3 g, 99%) as white solid, which was directly used for next reaction without further purification. #H NMR (MeOD, 600 MHz) δ 7.46 (2H, d, J=7.8 Hz), 7.12 (2H, d, J=7.8 Hz), 4.50 (1H, d, J=9.6 Hz), 3.85 (1H, d, J=12.6, 1.8 Hz), 3.66 (1H, dd, J=12.0, 5.4 Hz), 3.36 (1H, t, J=9.0 Hz), 3.24-3.28 (2H, m), 3.17 (1H, t, J=9.0 Hz), 2.13 (3H, s). ¹³C NMR (MeOD, 150 MHz) δ 138.90, 133.66, 131.33, 130.67, 89.79, 82.16, 79.81, 73.82, 71.50, 63.03, 21.24. HRMS (ESI-TOF) for C₁₃H₈O₅SNa⁺ [M+Na]⁺ calcd 309.0767, found 309.0772.

Compound 4:

To a solution of 3 (11.1 g, 38.8 mmol) in 48 mL of dry pyridine was added triphenylmethyl chloride (13.5 g, 46.6 mmol). The reaction was stirred for 16 h at 60° C. under argon. After removal of the solvent, the mixture was purified by flash column chromatography on silica gel (hexanes:AcOEt:MeOH 1:1:0.1) to give 4 (12.3 g, 60%) as white powder. ¹H NMR (MeOD, 600 MHz) δ 7.56 (2H, d, J=7.8 Hz), 7.47 (6H, d, J=7.8 Hz), 7.27 (6H, t, J=7.2 Hz), 7.22 (3H, t, J=7.2 Hz), 7.05 (2H, d, J=8.4 Hz), 4.58 (1H, d, J=9.6 Hz), 3.40-3.43 (2H, m), 3.31 (1H, m), 3.23-3.27 (3H, m), 2.27 (3H, s). ¹³C NMR (MeOD, 150 MHz) δ 145.69, 138.71, 133.62, 131.51, 130.77, 130.16, 128.87, 128.13, 89.46, 87.88, 80.98, 80.02, 73.93, 71.85, 65.14, 21.34. HRMS (ESI-TOF) for C₃₂H₃₂O₅SNa⁺ [M+Na]⁺ calcd 551.1863, found 551.1876.

Compound 5:

To a solution of 4 (21.1 g, 39.9 mmol) in 200 mL of dry N,N-dimethylformamide (DMF) was added sodium hydride (60% in mineral oil) (5.8 g, 143.6 mmol) at 0° C. The reaction was stirred for 1 h, followed by the addition of benzyl bromide (17.2 mL, 143.6 mmol) then stirred for 16 h under argon at ambient temperature. The reaction was quenched by MeOH and evaporated to dryness. The residue was diluted with AcOEt, the solution was washed with H₂O and brine, dried over MgSO₄, and evaporated to dryness. The mixture was purified by flash column chromatography on silica gel (hexanes:AcOEt 9:1) to give 5 (22.3 g, 70%) as white powder. ¹H NMR (CDCl₃, 600 MHz) δ 7.60 (2H, d, J=7.8 Hz), 7.50 (6H, d, J=7.8 Hz), 7.42 (2H, d, J=7.2 Hz), 7.34 (2H, t, J=7.2 Hz), 7.24-7.32 (12H, m), 7.18-7.23 (4H, m), 7.14-7.17 (2H, m), 7.05 (2H, d, J=7.8 Hz), 6.82 (2H, d, J=7.8 Hz), 4.91 (1H, d, J=10.8 Hz), 4.84 (1H, d, J=10.8 Hz), 4.80 (1H, d, J=10.8 Hz), 4.74 (1H, d, J=10.2 Hz), 4.64 (2H, dd, J=9.6, 5.4 Hz), 4.30 (1H, d, J=10.2 Hz), 3.74 (1H, t, J=9.6 Hz), 3.64 (1H, t, J=8.4 Hz), 3.60 (1H, d, J=9.6 Hz), 3.55 (1H, t, J=9.6 Hz), 3.42 (1H, m), 3.25 (1H, dd, J=10.2, 4.2 Hz), 2.30 (3H, s). ¹³C NMR (CDCl₃, 150 MHz) δ 144.14, 138.57, 138.43, 137.94, 137.90, 133.01, 130.10, 129.96, 129.07, 128.73, 128.67, 128.45, 128.42, 128.31, 128.20, 128.16, 128.15, 128.07, 128.01, 127.89, 127.20, 87.90, 87.07, 86.70, 80.96, 79.04, 78.04, 76.25, 75.61, 75.21, 62.68, 45.18, 21.37. HRMS (ESI-TOF) for C₅₃H₅₀O₅SNa⁺ [M+Na]⁺ calcd 821.3271, found 821.3310.

Compound 6:

To a solution of 5 (30.0 g, 37.5 mmol) in 1065 mL of aqueous acetic acid solution (AcOH:H₂O 4:1) was stirred for 3 h at 75° C. After removal of the solvent, the residue was purified by flash column chromatography on silica gel (hexanes:AcOEt 2:1) to give 6 (16.7 g, 80%) as white solid. ¹H NMR (CDCl₃, 600 MHz) δ 7.37-7.41 (4H, m), 7.25-7.33 (13H, m), 7.10 (2H, d, J=7.8 Hz), 4.91 (1H, d, J=10.2 Hz), 4.89 (1H, d, J=10.8 Hz), 4.84 (1H, d, J=10.8 Hz), 4.83 (1H, d, J=10.8 Hz), 4.74 (1H, d, J=10.8 Hz), 4.62 (1H, d, J=10.2 Hz), 3.83-3.86 (1H, m), 3.65-3.71 (2H, m), 3.54 (1H, t, J=9.6 Hz), 3.44 (1H, t, J=9.0 Hz), 3.33-3.36 (1H, m), 2.31 (3H, s), 1.87 (1H, t, J=6.6 Hz). ¹³C NMR (CDCl₃, 150 MHz) δ 138.51, 138.24, 138.14, 138.02, 132.85, 129.99, 129.63, 128.71, 128.66, 128.63, 128.40, 128.22, 128.16, 128.09, 127.98, 127.94, 87.99, 86.75, 81.27, 79.43, 77.81, 76.01, 75.69, 75.30, 62.34, 21.31. HRMS (ESI-TOF) for C₃₄H₃₆O₅SNa⁺ [M+Na]⁺ calcd 579.2176, found 579.2188.

Compound 7:

To a solution of 6 (5.0 g, 9.0 mmol) in 18 mL of dry pyridine was added acetic anhydride (1.0 mL). The reaction was stirred for 16 h at ambient temperature under argon. After removal of the solvent, the residue was diluted with AcOEt, the solution was washed with H₂O and brine, dried over MgSO₄ and evaporated to dryness. The mixture was purified by flash column chromatography on silica gel (hexanes:AcOEt 5:1) to give 7 (5.3 g, 99%) as white solid. ¹H NMR (CDCl₃, 600 MHz) δ 7.44 (2H, d, J=7.8 Hz), 7.38 (2H, d, J=7.8 Hz), 7.26-7.34 (11H, m), 7.22-7.24 (2H, m), 7.08 (2H, d, J=7.8 Hz), 4.91 (1H, d, J=10.2 Hz), 4.90 (1H, d, J=11.4 Hz), 4.83 (1H, d, J=10.8 Hz), 4.82 (1H, d, J=10.8 Hz), 4.71 (1H, d, J=10.2 Hz), 4.57 (1H, d, J=9.6 Hz), 4.55 (1H, d, J=10.8 Hz), 4.34 (1H, d, J=12.0 Hz), 4.17-4.20 (1H, m), 3.67-3.70 (1H, m), 3.49-3.50 (2H, m), 3.45 (1H, t, J=9.6 Hz), 2.32 (3H, s), 2.03 (3H, s). ¹³C NMR (CDCl₃, 150 MHz) δ 170.90, 138.44, 138.16, 138.13, 137.81, 132.98, 129.85, 128.76, 128.72, 128.68, 128.45, 128.30, 128.26, 128.15, 128.02, 88.00, 86.93, 81.07, 77.74, 76.08, 75.68, 75.32, 63.51, 21.35, 21.09. HRMS (ESI-TOF) for C₃₆H₃₈O₆SNa⁺ [M+Na]⁺ calcd 621.2281, found 621.2301.

Compound 8:

To a solution of 7 (5.5 g, 9.2 mmol) in 129 mL of aqueous acetone solution (acetone: H₂O 4:1) was added N-bromosuccinimide (1.7 g, 9.5 mmol). The reaction was stirred for 1 h at ambient temperature. After removal of the solvent, the residue was diluted with AcOEt, extracted with H₂O, aqueous sodium thiosulfate (NaS₂O₃) solution, brine then dried over MgSO₄. The mixture was purified by flash column chromatography on silica gel (hexane: AcOEt 2:1) to give 8 (3.1 g, 69%, α/β=1:1) as white solid. ¹H NMR (CDCl₃, 600 MHz) δ 7.24-7.35 (30H, m), 5.18 (1H, t, J=3.0 Hz), 4.96 (1H, d, J=10.2 Hz), 4.94 (2H, d, J=10.8 Hz), 4.86 (1H, d, J=10.8 Hz), 4.85 (1H, d, J=10.2 Hz), 4.84 (1H, d, J=10.2 Hz), 4.80 (1H, d, J=10.8 Hz), 4.76 (2H, d, J=11.4 Hz), 4.71 (1H, dd, J=7.2, 5.4 Hz), 4.68 (1H, d, J=12.0 Hz), 4.55 (2H, d, J=10.8 Hz), 4.34 (1H, dd, J=12.0, 1.2 Hz), 4.23-4.28 (2H, m), 4.17 (1H, dd, J=12.0, 4.8 Hz), 4.06-4.09 (1H, m), 3.98 (1H, t, J=9.6 Hz), 3.67 (1H, t, J=8.4 Hz), 3.50-3.56 (3H, m), 3.48 (1H, t, J=9.0 Hz), 3.37-3.40 (2H, m), 3.01 (1H, d, J=3.0 Hz), 2.02 (3H, s), 2.01 (3H, s). ¹³C NMR (CDCl₃, 150 MHz) δ 138.64, 138.49, 138.39, 137.96, 137.89, 137.81, 128.75, 128.70, 128.68, 128.65, 128.63, 128.33, 128.29, 128.27, 128.22, 128.20, 128.14, 128.06, 127.99, 127.93, 97.62, 91.33, 84.71, 83.20, 81.82, 80.18, 77.39, 75.96, 75.92, 75.23, 75.21, 74.98, 73.47, 73.19, 69.02, 63.35, 63.27, 21.06. HRMS (ESI-TOF) for C₂₉H₃₂O₇Na⁺ [M+Na]⁺ calcd 515.2040, found 515.2052.

Synthesis of Acceptor 18

Compound 13:

To a solution of D-Lyxose 12 (20 g, 133 mmol) in 200 mL of anhydrous N,N-dimethylformamide (DMF) was added 2-methoxypropene (15 mL, 160 mmol) and camphor-10-sulfonic acid (CSA) (3 g, 13.3 mmol) at 0° C. The reaction was stirred for 16 h at ambient temperature under argon. The solution was quenched with triethylamine (Et₃N), evaporated to dryness and directly purified by flash column chromatography on silica gel (hexanes:AcOEt:MeOH 1:1:0.2) to give 13 (21 g, 83%) as white solid. ¹H NMR (CDCl₃, 600 MHz): δ 5.22 (s, 1H), 4.78 (dd, 1H, J=6.0, 3.6 Hz), 4.53 (d, 1H, J=6.0 Hz), 4.17 (m, 1H, J=6.6, 4.8 Hz), 3.82 (dd, 1H, J=11.7, 4.8 Hz), 3.71 (dd, 1H, J=11.7, 6.6 Hz), 1.40 (s, 3H), 1.29 (s, 3H). ¹³C NMR (CDCl₃, 150 MHz): δ 113.62, 102.27, 87.42, 81.73, 81.35, 61.37, 26.46, 25.02. HRMS (ESI-TOF) for C₈H₁₄O₅Na⁺ [M+Na]⁺ calcd 213.0733, found 213.0751.

Compound 14:

To a stirred solution of 13 (21 g, 110 mmol) in 140 mL of dry pyridine was added triphenylmethyl chloride (37.8 g, 132 mmol). The reaction was stirred for 16 h at 60° C. under argon. The solution was concentrated to dryness, the residue was dissolved with ethyl acetate (AcOEt), washed with H₂O, brine and dried over magnesium sulfate (MgSO₄) then evaporated. The mixture was purified by flash column chromatography on silica gel (hexanes:AcOEt 1:2) to give 14 (36.5 g, 77%) as white powder. ¹H NMR (CDCl₃, 600 MHz): δ 7.46 (m, 6H), 7.27 (m, 6H), 7.21 (m, 3H), 5.36 (d, 1H, J=1.8 Hz), 4.73 (dd, 1H, J=6.0, 4.8 Hz), 4.57 (d, 1H, J=6.0 Hz), 4.31 (ddd, 1H, J=4.8, 4.8, 7.8 Hz), 3.41 (dd, 1H, J=9.6, 4.8 Hz), 3.37 (dd, 1H, J=9.6, 7.8 Hz), 2.41 (m, 1H, J=1.8 Hz), 1.27 (s, 3H), 1.25 (s, 3H). ¹³C NMR (CDCl₃, 150 MHz): δ 143.95, 128.82, 127.75, 126.95, 112.48, 101.22, 86.85, 85.41, 80.11, 79.70, 61.85, 26.02, 25.09. HRMS (ESI-TOF) for C₂₇H₂₈O₅Na⁺ [M+Na]⁺ calcd 455.1829, found 455.1833.

Compound 15:

To a stirred solution of 14 (8.4 g, 19.4 mmol) in 40 mL of anhydrous tetrahydrofurane (THF) was added lithium bis(trimethylsilyl)amide (LHMDS) (20 mL of 1M solution in THF, 20 mmol) at 0° C., the reaction was stirred for 1 h under argon. To a stirred solution of Wittig reagent C₁₃H₂₇PPh₃Br (20.1 g, 38.2 mmol), prepared from 1-bromotridecane (C₁₃H₂₇Br) and triphenylphosphine (PPh₃) refluxed in toluene for 5 days, in 83 mL of anhydrous THF was added LHMDS (40 mL of 1M solution in THF, 40 mmol) at 0° C., the reaction was stirred for 1 h under argon to produce the bright orange ylide. The solution of 14 was added dropwise to the ylide at 0° C., and the reaction was allowed to warm to ambient temperature and stirred for 9 h under argon. The resulting solution was quenched with MeOH and evaporated to dryness. The residue was diluted with AcOEt, extracted with H₂O and brine, dried over MgSO₄ then concentrated. The mixture was purified by flash column chromatography on silica gel (hexanes:AcOEt 15:1) to give 15 (8.7 g, 75%) as colorless oil. ¹H NMR (CDCl₃, 600 MHz): δ 7.40-7.45 (m, 9H), 7.25-7.30 (m, 9H), 7.19-7.23 (m, 5H), 5.49-5.57 (m, 3H, J=6.6 Hz), 4.90 (t, 1H, J=6.6 Hz), 4.43 (t, 1.5H, J=6.6 Hz), 4.25 (dd, 0.5H, J=6.6, 4.6 Hz), 4.20 (dd, 1H, J=6.6, 4.5 Hz), 3.74 (m, 1H), 3.68 (m, 0.5H), 3.22 (dd, 0.5H, J=9.6, 5.0 Hz), 3.15 (dd, 1H, J=9.3, 5.1 Hz), 3.10 (m, 1.5H), 2.37 (m, 1.5H), 1.90-2.00 (m, 2H), 1.75 (m, 1H), 1.47 (m, 5H), 1.37 (m, 5H), 1.19-1.33 (m, 35H), 0.86 (t, 5H, J=7.1 Hz). ¹³C NMR (CDCl₃, 150 MHz): δ 144.07, 137.58, 135.56, 128.90, 128.02, 127.24, 125.41, 125.15, 108.58, 108.50, 86.90, 86.84, 79.14, 77.86, 77.74, 73.21, 69.51, 69.43, 65.19, 64.84, 32.45, 32.13, 29.89, 29.86, 29.81, 29.71, 29.69, 29.57, 29.50, 29.47, 29.11, 27.80, 27.59, 27.55, 25.26, 22.91, 14.35. HRMS (ESI-TOF) for C₄₀H₅₄O₄Na⁺ [M+Na]⁺ calcd 621.3914, found 621.3919.

Compound 16:

Compound 16 was prepared from catalytic hydrogenation of 15 (1 g, 1.7 mmol) in 10 mL of anhydrous MeOH containing catalytic amount of palladium hydroxide on carbon (20% Pd). The suspension was stirred for 4 h in an H₂ atmosphere. The solution was filtered through Celite 545 to remove the catalyst, evaporated to dryness then purified by flash column chromatography on silica gel (hexane: AcOEt 20:1) to give 16 (903 mg, 90%) as white solid. ¹H NMR (CDCl₃, 600 MHz): δ 7.43 (m, 6H), 7.27 (m, 6H), 7.21 (m, 3H), 4.12 (dd, 1H, J=6.4, 3.7 Hz), 4.05 (ddd, 1H, J=9.9, 6.4, 3.6 Hz), 3.69 (m, 1H, J=6.0, 6.0, 5.8, 3.7 Hz), 3.18 (m, 2H, J=9.5, 9.5, 6.0, 5.8 Hz), 2.29 (d, 1H, J=6.0 Hz), 1.60-1.67 (m, 1H), 1.45-1.49 (m, 1H), 1.43 (s, 3H), 1.34-1.38 (m, 1H), 1.33 (s, 3H), 1.20-1.30 (m, 23H), 0.86 (t, 3H, J=7.2 Hz). ¹³C NMR (CDCl₃, 150 MHz): δ 144.09, 128.91, 128.05, 127.26, 107.95, 87.02, 77.67, 69.15, 65.43, 32.15, 29.92, 29.88, 29.83, 29.77, 29.58, 27.60, 26.99, 25.43, 22.92, 14.36. HRMS (ESI-TOF) for C₄₀H₅₆O₄Na⁺ [M+Na]⁺ calcd 623.4071, found 623.4112.

Compound 17:

To a solution of 16 (5 g, 8.3 mmol) and 4 Å molecular sieves (1 g) in 39 mL of anhydrous CH₂Cl₂ was added 2,6-lutidine (3.5 mL, 30 mmol) at ambient temperature. When the solution was cooled to −45° C., trifluoromethanesulfonic anhydride (Tf₂O) (2.67 mL, 15.9 mmol) was added dropwise and the reaction was stirred for 1 h under argon. Followed by the addition of tetramethylguanidinium azide (TMGA) (3.9 g, 25 mmol), the reaction was allowed to warm to ambient temperature and stirred for 16 h under argon. The resulting solution was filtered through Celite 545 to remove 4 Å molecular sieves and the residue was diluted with CH₂Cl₂, extracted with H₂O and brine, dried over MgSO₄ then evaporated. The mixture was simply purified by flash column chromatography on silica gel (hexanes:AcOEt 20:1) to remove most of the impurities and directly used for the next step.

Compound 18:

To a solution of 17 in 20 mL of anhydrous CH₂Cl₂ was added tetrafluoroacetic acid/tetrafluoroacetic anhydride (TFA/TFAA 1.8 M/1.8 M in CH₂Cl₂) (14 mL, 24.9 mmol) at 4° C. and stirred for 15 min under argon. The reaction was quenched by adding 10 mL of Et3N then poured into 200 mL of methanol (MeOH) and stirred for another 15 min. After removal of the solvent, the residue was diluted with AcOEt, extracted with H₂O, saturated NaHCO₃ solution and brine then dried over MgSO₄. The organic layer was concentrated in vacuo and the mixture was purified by flash column chromatography on silica gel (hexanes:AcOEt 10:1) to give 18 (2 g, two steps 63%) as yellow oil. ¹H NMR (CDCl₃, 600 MHz): δ 4.16 (ddd, 1H, J=9.7, 5.6, 3.6 Hz), 3.97 (dd, 1H, J=11.6, 4.2 Hz), 3.94 (dd, 1H, J=9.4, 5.6 Hz), 3.85 (dd, 1H, J=11.6, 5.4 Hz), 3.45 (ddd, 1H, J=9.4, 5.4, 4.2 Hz), 1.50-1.62 (m, 2H, J=9.7, 3.6 Hz), 1.41 (s, 3H), 1.31-1.37 (m, 6H), 1.22-1.30 (m, 22H), 0.86 (t, 3H, J=6.9, 6.9 Hz). ¹³C NMR (CDCl₃, 150 MHz): δ 108.66, 77.96, 76.91, 64.18, 61.39, 32.14, 29.90, 29.87, 29.81, 29.80, 29.75, 29.60, 29.58, 28.25, 26.74, 25.77, 22.91, 14.34. HRMS (ESI-TOF) for C₂₁H₄₁N₃O₃H⁺ [M+H]⁺ calcd 383.3148, found 356.3157 (—N₂).

Synthesis of α-Glucosylceramide Analogues 24-26

Compound 19:

To a solution of glucosyl donor 8 (2.9 g, 5.9 mmol), dimethylsulfide (590 μL, 7.8 mmol), 4 Å molecular sieve (500 mg) and 2-chloropyridine (1.8 mL, 19.5 mmol) in anhydrous CH₂Cl₂ (15 mL) was added trifluoromethanesulfonic anhydride (1 mL, 6 mmol) at −45° C. under argon. The reaction was stirred for 20 min at −45° C., 20 min at 0° C. and another 20 min at ambient temperature, followed by the addition of acceptor 18 (1.5 g, 3.9 mmol) in 5 mL of CH₂Cl₂. The reaction was stirred for 16 h at ambient temperature under argon.

The solution was filtered through Celite 545 to remove molecular sieve. After removal of the solvent, the residue was diluted with AcOEt, the solution was washed with H₂O and brine, dried over MgSO₄ and evaporated to dryness. The mixture was purified by flash column chromatography on silica gel (hexanes:AcOEt 10:1) to give 19 as colorless oil (2 g, 60%). ¹H NMR (CDCl₃, 600 MHz) δ 7.36 (2H, d, J=7.8 Hz), 7.24-7.33 (13H, m), 4.97 (1H, d, J=10.8 Hz), 4.86 (1H, d, J=10.8 Hz), 4.85 (1H, d, J=3.6 Hz), 4.78 (1H, d, J=10.8 Hz), 4.72 (1H, d, J=12.0 Hz), 4.68 (1H, d, J=12.0 Hz), 4.54 (1H, d, J=10.8 Hz), 4.21-4.26 (2H, m), 4.08-4.11 (1H, m), 4.02-4.07 (2H, m), 3.97 (1H, dd, J=9.6, 5.4 Hz), 3.84-3.87 (1H, m), 3.60 (1H, dd, J=10.8, 7.2 Hz), 3.54 (1H, dd, J=9.6, 3.6 Hz), 3.44-3.48 (2H, m), 2.00 (3H, s), 1.57-1.61 (1H, m), 1.50-1.55 (1H, m), 1.37 (3H, s), 1.22-1.35 (27H, m), 0.86 (3H, t, J=7.2 Hz). ¹³C NMR (CDCl₃, 150 MHz) δ 170.93, 138.82, 138.58, 138.05, 128.68, 128.61, 128.59, 128.34, 128.31, 128.13, 127.90, 127.86, 81.82, 80.26, 77.97, 77.30, 75.93, 75.61, 75.24, 72.92, 69.50, 69.34, 63.26, 59.99, 32.13, 29.90, 29.87, 29.82, 29.77, 29.57, 29.54, 28.42, 26.73, 25.89, 22.90, 21.03, 14.33. HRMS (ESI-TOF) for C₅₀H₇₁N₃O₉Na⁺ [M+Na]⁺ calcd 880.5083, found 880.5124.

Compound 20:

To a solution of 19 (269 mg, 0.31 mmol) in pyridine/H₂O (10:1, 12 mL) was added triphenylphosphine (165 mg, 0.63 mmol). The reaction was stirred for 16 h at 45° C. under argon. After removal of the solvent, the residue was diluted with AcOEt, extracted with H₂O, brine and dried over MgSO₄ then evaporated to dryness. The mixture was used for next step without prior purification.

Compound 21:

To a solution of compound 20 in 36 mL of anhydrous CH₂Cl₂ was added hexacosanoic acid (159 mg, 0.4 mmol), Et3N (88 μL), EDC (90 mg, 0.47 mmol) and HBTu (178 mg, 0.47 mmol). The reaction was stirred for 16 h at ambient temperature under argon. After removal of the solvent, the residue was diluted with AcOEt, extracted with H₂O, brine and dried over MgSO₄ then evaporated to dryness. The mixture was purified by flash column chromatography on silica gel (hexanes:AcOEt 4:1) to give 21 as white solid (293 mg, 78%, two steps).

Compound 22:

To a solution of 21 (293 mg, 0.24 mmol) in 50 mL of co-solvent (MeOH:CH₂Cl₂ 1:1) was added sodium methoxide (0.024 mmol) and stirred for 6 h under argon at ambient temperature. The reaction was neutralized by Amberlite IR-120 and filtered. After removal of the solvent, the residue was used for next step without prior purification.

Compound 23:

The hydrolyzed compound 22 was dissolved in 50 mL of aqueous acetic acid solution (AcOH:H₂O 4:1) and stirred for 16 h at 60° C. After removal of the solvent, the mixture was purified by flash column chromatography on silica gel (hexanes:AcOEt:MeOH 1:1:0.1).

The deacetonide derivative 23 was dissolved in 50 mL of co-solvent (MeOH:CHCl₃ 4:1) containing palladium hydroxide on carbon (20% Pd) (cat.) and stirred for 16 h in an H₂ atmosphere. The solution was filtered through Celite 545 to remove the catalyst and evaporated to dryness, the mixture was purified by flash column chromatography on silica gel (MeOH:CHCl₃ 1:9) and eluted with LH20 (MeOH:CHCl₃ 1:1) to give 24 (72 mg, 35% for three steps) as white solid. ¹H NMR (MeOD-CDCl₃ 1:1, 600 MHz) δ: 4.83 (s, 1H), 4.15 (d, J=4.2 Hz, 1H), 3.84 (dd, J=10.8, 4.2 Hz, 1H), 3.76 (d, J=12.0 Hz, 1H), 3.64-3.70 (m, 2H), 3.60 (t, J=9.6 Hz, 1H), 3.51-3.57 (m, 3H), 3.41 (d, J=9.6 Hz, 1H), 3.31 (m, 1H), 2.17 (t, J=7.2 Hz, 2H), 1.50-1.65 (m, 4H), 1.19-1.39 (m, 68H), 0.85 (t, J=6.6 Hz, 6H). ¹³C NMR (MeOD-CDCl₃ 1:1, 150 MHz) δ: 175.29, 100.06, 75.05, 74.58, 73.03, 72.75, 72.62, 71.01, 67.78, 62.22, 51.11, 37.07, 32.93, 32.62, 30.49, 30.45, 30.40, 30.35, 30.25, 30.13, 30.05, 30.04, 26.61, 26.58, 23.34, 14.47. HRMS (MALDI-TOF) for C₅₀H₉₉NO₉Na⁺ [M+Na]⁺ calcd 880.7223, found 880.7212.

Compound 25 was synthesized using the similar procedure as compound 24. ¹H NMR (MeOD-CDCl₃ 1:1, 600 MHz) δ: 7.09 (dd, J=8.4, 5.4 Hz, 2H), 6.90 (t, J=9.0 Hz, 2H), 4.82 (d, J=3.6 Hz, 1H), 4.14-4.18 (m, 1H), 3.84 (dd, J=10.2, 4.8 Hz, 1H), 3.76 (dd, J=12.0, 2.4 Hz, 1H), 3.64-3.68 (m, 2H), 3.60 (t, J=9.0 Hz, 1H), 3.51-3.56 (m, 3H), 3.41 (dd, J=9.6, 3.6 Hz, 1H), 3.31 (m, 1H), 2.54 (t, J=7.8 Hz, 2H), 2.17 (t, J=7.8 Hz, 2H), 1.51-1.65 (m, 6H), 1.20-1.39 (m, 36H), 0.85 (t, J=6.6 Hz, 3H). ¹³³³³C NMR (MeOD-CDCl₃ 1:1, 150 MHz) δ: 175.30, 162.67, 161.07, 139.18, 139.16, 130.34, 130.29, 115.46, 115.32, 100.00, 75.03, 74.52, 72.97, 72.68, 72.55, 70.93, 67.71, 62.15, 51.11, 51.03, 37.06, 37.00, 35.72, 32.90, 32.58, 32.32, 30.45, 30.41, 30.35, 30.30, 30.22, 30.15, 30.11, 30.05, 30.00, 29.82, 26.57, 26.53, 23.29, 14.44. HRMS (ESI-TOF) for C₄₁H₇₂FNO₉Na⁺ [M+Na]⁺ calcd 764.5083, found 764.5066.

Compound 26 was synthesized using the similar procedure as compound 24. ¹H NMR (MeOD-CDCl₃ 1:1, 600 MHz) δ: 7.10 (d, J=8.4 Hz, 2H), 6.99 (t, J=7.8 Hz, 2H), 6.92 (m, 2H), 6.84 (d, J=7.8 Hz, 2H), 4.83 (d, J=3.0 Hz, 1H), 3.85 (dd, J=10.2, 4.2 Hz, 1H), 3.77 (d, J=11.4 Hz, 1H), 3.67 (m, 2H), 3.61 (t, J=9.6 Hz, 1H), 3.55 (m, 3H), 3.42 (dd, J=9.0, 3.0 Hz, 1H), 3.33 (m, 1H), 2.55 (t, J=7.8 Hz, 2H), 2.18 (t, J=7.8 Hz, 2H), 1.50-1.64 (m, 6H), 1.20-1.40 (m, 36H), 0.85 (t, J=6.6 Hz, 3H). ¹³C NMR (MeOD-CDCl₃ 1:1, 150 MHz) δ: 175.34, 160.27, 158.67, 156.22, 154.38, 138.73, 130.34, 120.76, 120.71, 119.10, 116.87, 116.72, 100.15, 75.10, 74.66, 73.15, 72.85, 72.65, 71.09, 67.80, 62.26, 51.21, 37.09, 35.90, 32.95, 32.68, 32.44, 30.55, 30.51, 30.47, 30.40, 30.35, 30.28, 30.26, 30.17, 30.11, 30.00, 26.67, 26.63, 23.38, 14.47. HRMS (ESI-TOF) for C₄₇H₇₆FNO₁₀Na⁺ [M+H]⁺ calcd 834.5526, found 834.5538.

Synthesis of Fluorinated Donor 38

Compound 32:

To a solution of 1,2,3,4,6-Penta-O-acetyl-3-D-glucopyranose 1 in dry CH₂Cl₂ was added 4-methoxyphenol and BF₃OEt₂ at 0° C., the reaction was stirred for 16 h at ambient temperature under argon. The resulting solution was directly extracted with saturated NaHCO₃ solution and brine, dried over MgSO₄ and evaporated. The product was recrystallized from a solution of AcOEt-hexanes to give 32 as white solid.

Compound 33:

To a solution of 32 in dry MeOH was added catalytic amount of sodium methoxide (NaOMe) and stirred for 3 h at ambient temperature. The reaction was neutralized by adding Amberlite IR-120 and filtered, the resulting solution was concentrated to dryness to give 33 as white solid, which was directly used for next reaction without further purification.

Compound 34:

To a solution of 33 in dry co-solvent (DMF and CH₃CN) was added benzaldehyde dimethylacetal and catalytic amount of sodium methoxide (NaOMe). The reaction was stirred for 16 h at ambient temperature. The solution was neutralized by adding Et₃N and concentrated. The mixture was dissolved in ethyl acetate, washed with saturated NaHCO₃ solution and brine, dried over MgSO₄ and evaporated. The product was recrystallized from a solution of AcOEt-hexanes to give 34 as white solid.

Compound 35:

To a solution of 34 in dry N,N-dimethylformamide (DMF) was added sodium hydride (60% in mineral oil) at 0° C. The reaction was stirred for 1 h, followed by the addition of benzyl bromide and the reaction was stirred for 16 h under argon at ambient temperature. The solution was quenched by MeOH and evaporated to dryness. The residue was diluted with AcOEt, the solution was washed with H₂O and brine, dried over MgSO₄, and evaporated to dryness. The product was recrystallized from a solution of AcOEt-hexanes to give 35 as white solid.

Compound 36:

To a solution of 35 in CH₂Cl₂ was added triethylsilane and trifluoroacetic acid (TFA) at 0° C. The reaction was stirred for 3 h at ambient temperature. The solution was directly washed with H₂O, saturated NaHCO₃ solution and brine, dried over MgSO₄, and evaporated to dryness. The product was recrystallized from a solution of AcOEt-hexanes to give 36 as white solid.

Compound 37:

To a solution of 36 in CH₂Cl₂ was added diethylaminosulfur trifluoride (DAST). The reaction was stirred for 16 h at 45° C. and the solution was directly washed with H₂O, saturated NaHCO₃ solution and brine, dried over MgSO₄, and evaporated to dryness. The residue was purified by flash column chromatography on silica gel to give compound 37 as colorless oil.

Compound 38:

To a solution of 37 in dry co-solvent (toluene, H₂O and CH₃CN) was added ceric ammonium nitrate (CAN). The reaction was stirred for 10 min at ambient temperature. The solution was extracted with ethyl acetate, washed with H₂O, saturated NaHCO₃ solution and H₂O, dried over MgSO₄, and evaporated to dryness. The residue was purified by flash column chromatography on silica gel to give compound 38 as colorless oil.

Synthesis of Fluorinated Analogue 43

Compound 39:

To a solution of donor 38, dimethylsulfide, 4 Å molecular sieve and 2-chloropyridine in anhydrous CH₂Cl₂ was added trifluoromethanesulfonic anhydride at −45° C. under argon. The reaction was stirred for 20 min at −45° C., 20 min at 0° C. and another 20 min at ambient temperature, followed by the addition of acceptor 18 in CH₂Cl₂. The reaction was stirred for 16 h at ambient temperature under argon. The solution was filtered through Celite 545 to remove molecular sieve. After removal of the solvent, the residue was diluted with AcOEt, the solution was washed with H₂O and brine, dried over MgSO₄ and evaporated to dryness. The mixture was purified by flash column chromatography on silica gel to give 39.

Compound 40:

To a solution of 39 in pyridine/H₂O (10:1) was added triphenylphosphine. The reaction was stirred for 16 h at 45° C. under argon. After removal of the solvent, the residue was diluted with AcOEt, extracted with H₂O, brine and dried over MgSO₄ then evaporated to dryness. The mixture was used for next step without prior purification.

Compound 41:

To a solution of compound 40 in anhydrous CH₂Cl₂ was added 4-(4-fluorophenoxy) phenylundecanoic acid, Et₃N, EDC and HBTu. The reaction was stirred for 16 h at ambient temperature under argon. After removal of the solvent, the residue was diluted with AcOEt, extracted with H₂O, brine and dried over MgSO₄ then evaporated to dryness. The mixture was purified by flash column chromatography on silica gel to give 41.

Compound 42:

To a solution of compound 41 in aqueous acetic acid solution (AcOH:H₂O 4:1) and stirred for 16 h at 60° C. After removal of the solvent, the mixture was dissolved in ethyl acetate, washed with saturated NaHCO₃ solution and brine, dried over MgSO₄ and evaporated. The residue was purified by flash column chromatography on silica gel to give 42.

The deacetonide derivative 42 was dissolved in co-solvent (MeOH:CHCl₃ 4:1) containing palladium hydroxide on carbon (20% Pd) (cat.) and stirred for 16 h in an H₂ atmosphere. The solution was filtered through Celite 545 to remove the catalyst and evaporated to dryness, the mixture was purified by flash column chromatography on silica gel and eluted with LH20 to give 43. ¹H NMR (MeOD-CDCl₃ 1:1, 600 MHz) δ: 7.09 (1H, d, J=8.4 Hz), 6.96-6.99 (2H, m), 6.91-6.92 (2H, m), 6.82-6.84 (2H, m), 4.84 (1H, t, J=3.6 Hz), 4.25 (0.5H, t, J=9.0 Hz), 4.15-4.18 (2H, m), 3.82-3.85 (2H, m), 3.75-3.77 (1H, m), 3.69-3.72 (1H, m), 3.64-3.68 (2H, m), 3.50-3.54 (2H, m), 3.44 (1H, dd, J=9.6, 3.6 Hz), 2.54 (2H, t, J=7.2 Hz), 2.17 (2H, t, J=7.8 Hz), 1.50-1.64 (7H, m), 1.22-1.27 (41H, m), 0.84 (3H, t, J=7.2 Hz). ¹³C NMR (MeOD-CDCl₃ 1:1, 150 MHz) δ: 175.28, 160.20, 158.61, 156.16, 154.30, 138.67, 130.28, 120.70, 120.64, 119.04, 116.81, 116.66, 99.94, 90.61, 89.41, 75.04, 72.72, 72.59, 72.56, 72.42, 72.37, 70.82, 70.66, 67.82, 61.21, 51.10, 37.05, 35.83, 32.91, 32.61, 32.36, 30.46, 30.43, 30.39, 30.33, 30.27, 30.19, 30.18, 30.09, 30.03, 29.92, 26.63, 26.55, 23.32, 14.41. HRMS (ESI-TOF) for C₄₇H₇₅F₂NO₉H⁺ [M+H]⁺ calcd 836.5498, found 836.5483.

Synthesis of Fluorinated Donor 48

Compound 44:

To a solution of 32 in dry pyridine was added triphenylmethyl chloride. The reaction was stirred for 16 h at 60° C. under argon. After removal of the solvent, the mixture was purified by flash column chromatography on silica gel to give 44.

Compound 45:

To a solution of 44 in N,N-dimethylformamide (DMF) was added sodium hydride (60% in mineral oil) at 0° C. The reaction was stirred for 1 h, followed by the addition of benzyl bromide and stirred for 16 h under argon at ambient temperature. The reaction was quenched by MeOH and evaporated to dryness. The residue was diluted with AcOEt, the solution was washed with H₂O and brine, dried over MgSO₄, and evaporated to dryness. The mixture was purified by flash column chromatography on silica gel to give 45.

Compound 46:

To a solution of 45 in aqueous acetic acid solution (AcOH:H₂O 4:1) was stirred for 3 h at 75° C. After removal of the solvent, the mixture was diluted with AcOEt, the solution was washed with H₂O and brine, dried over MgSO₄, and evaporated to dryness. The residue was purified by flash column chromatography on silica gel to give 46.

Compound 47:

To a solution of 46 in CH₂Cl₂ was added diethylaminosulfur trifluoride (DAST). The reaction was stirred for 16 h at 45° C. and the solution was directly washed with H₂O, saturated NaHCO₃ solution and brine, dried over MgSO₄, and evaporated to dryness. The residue was purified by flash column chromatography on silica gel to give compound 47.

Compound 48:

To a solution of 47 in dry co-solvent (toluene, H₂O and CH₃CN) was added ceric ammonium nitrate (CAN). The reaction was stirred for 10 min at ambient temperature. The solution was extracted with ethyl acetate, washed with H₂O, saturated NaHCO₃ solution and H₂O, dried over MgSO₄, and evaporated to dryness. The residue was purified by flash column chromatography on silica gel to give compound 48 as colorless oil.

Synthesis of Fluorinated Analogue 53

Compound 49:

To a solution of donor 48, dimethylsulfide, 4 Å molecular sieve and 2-chloropyridine in anhydrous CH₂Cl₂ was added trifluoromethanesulfonic anhydride at −45° C. under argon. The reaction was stirred for 20 min at −45° C., 20 min at 0° C. and another 20 min at ambient temperature, followed by the addition of acceptor 18 in CH₂Cl₂. The reaction was stirred for 16 h at ambient temperature under argon. The solution was filtered through Celite 545 to remove molecular sieve. After removal of the solvent, the residue was diluted with AcOEt, the solution was washed with H₂O and brine, dried over MgSO₄ and evaporated to dryness. The mixture was purified by flash column chromatography on silica gel (hexanes:AcOEt 10:1) to give 49.

Compound 50:

To a solution of 49 in pyridine/H₂O (10:1) was added triphenylphosphine. The reaction was stirred for 16 h at 45° C. under argon. After removal of the solvent, the residue was diluted with AcOEt, extracted with H₂O, brine and dried over MgSO₄ then evaporated to dryness. The mixture was used for next step without prior purification.

Compound 51:

To a solution of compound 50 in dry CH₂Cl₂ was added 4-(4-fluorophenoxy) phenylundecanoic acid, Et₃N, EDC and HBTu. The reaction was stirred for 16 h at ambient temperature under argon. After removal of the solvent, the mixture was diluted with AcOEt, extracted with H₂O, brine and dried over MgSO₄ then evaporated to dryness. The residue was purified by flash column chromatography on silica gel to give 51.

Compound 52:

To a solution of compound 51 was dissolved in aqueous acetic acid solution (AcOH:H₂O 4:1) and stirred for 16 h at 60° C. After removal of the solvent, the mixture was diluted with AcOEt, extracted with H₂O, brine and dried over MgSO₄ then evaporated to dryness. The residue was purified by flash column chromatography on silica gel.

The deacetonide derivative 52 was dissolved co-solvent (MeOH:CHCl₃ 4:1) containing palladium hydroxide on carbon (20% Pd) (cat.) and stirred for 16 h in an H₂ atmosphere. The solution was filtered through Celite 545 to remove the catalyst and evaporated to dryness, the mixture was purified by flash column chromatography on silica gel and eluted with LH20 to give 53. ¹H NMR (MeOD-CDCl₃ 1:1, 600 MHz) δ: 7.51 (0.6H, d, J=8.4 Hz), 7.09-7.11 (2H, m), 6.97-7.00 (2H, m), 6.91-6.94 (2H, m), 6.83-6.85 (2H, m), 4.85 (1H, d, J=3.6 Hz), 4.49-4.59 (2H, m), 4.15-4.18 (1H, m), 3.85 (1H, dd, J=10.8, 4.8 Hz), 3.61-3.71 (3H, m), 3.52-3.58 (2H, m), 3.43 (1H, d, J=9.6, 3.6 Hz), 3.36 (1H, t, J=9.0 Hz), 2.55 (2H, t, J=7.8 Hz), 2.18 (2H, t, J=7.8 Hz), 1.51-1.64 (6H, m), 1.23-1.39 (39H, m), 0.85 (3H, t, J=7.2 Hz). ¹³C NMR (MeOD-CDCl₃ 1:1, 150 MHz) δ: 175.06, 174.98, 159.99, 158.40, 155.94, 154.09, 154.08, 138.48, 130.09, 120.52, 120.46, 118.85, 116.63, 116.47, 100.02, 83.18, 82.04, 74.72, 74.31, 72.44, 72.38, 71.78, 71.67, 69.58, 69.54, 50.88, 50.79, 36.88, 36.83, 35.64, 32.64, 32.42, 32.17, 30.29, 30.24, 30.20, 30.14, 30.08, 30.01, 29.99, 29.91, 29.85, 29.74, 26.42, 26.38, 23.13, 14.26. HRMS (ESI-TOF) for C₄₇H₇₅F₂NO₉H⁺ [M+H]⁺ calcd 836.5483, found 836.5498.

Biological Studies

Injection of Glycolipid Analogs in Mice

All the glycolipids were dissolved in 100% DMSO at a concentration of 1-2 mg/ml. For in vivo experiments, all compounds were diluted to 10 μg/ml in saline just before injection of 100 μl diluted glycolipid or 100 μl 1% DMSO into mice. Pathogen-free C57BL/6 female mice aged 6-12 weeks were obtained from the National Laboratory Animal Center (Taipei, Taiwan). Jα18 knockout (KO) B6 mice were the gifts from Dr. Masaru Taniguchi (RIKEN Research Center for Allergy and Immunology, Yokohama, Japan). All the mice were maintained in pathogen free vivarium of Institute of Cellular and Organismic Biology, Academia Sinica (Taipei, Taiwan).

Determination of Murine Cytokine/Chemokine Secretions

B6 WT or Jα18 KO mice were intravenously injected with vehicle or glycolipids at 0.1 or 1 μg/mouse. Serum was collected at 2 and 18 h after injection for measurement of cytokines/chemokines by Beadlyte® Mouse Cytokine kit (Millipore, N.Y.) and read by a Luminex® 200™ system (Luminex, Austin, Tex.).

FACS Analyses of Mouse Immune Cells after the Specific Glycolipid Stimulation

B6 WT or Jα18 KO mice treated with specific glycolipid (1 μg/mouse) or vehicle (1% DMSO in PBS) were sacrificed at 72 hr post-injection and their spleens were harvested. After pressing spleens through 70 um strainer and lysis of erythrocytes, the nucleated cells were resuspended in PBS buffer containing azide (0.05%) and stained with antibodies recognizing the indicated cell surface antigens for 30 min at 4° C. After washing, the splenocytes were subjected to FACS analysis. The antibodies against CD3, CD4, CD8β, CD11c, CD80, and CD86 were obtained from BD Bioscience-Pharmingen.

Binding Strengths of the Binary Complex Between mCD1d and Glycolipid

Different concentrations of mCD1d^(di)-glycolipid complexes coated on the ELISA plate were incubated with the saturated amounts of L363 antibody (BioLegend) conjugated with biotin, followed by streptavidin-HRP detection and ELISA measurement. The KD between L363 antibody and the indicated mCD1d^(di)-glycolipid complex was calculated from the linear regression of the Scatchard transformation of the L363 antibody binding curve using GraphPad Prism software. L363 was found to recognize the mCD1d^(di)-7DW8-5-Glc complex and mCD1d^(di)-7DW8-5 complex with similar binding strength. Next, the KD of the binary complex was determined as follows. Different concentrations of glycolipids were incubated with fixed amounts of mCD1d dimer at 37° C. overnight, and then mCD1d^(di)-glycolipid complexes were coated on the 96 well ELISA plate at 4° C. overnight. After washing and blocking with BSA at room temperature (RT) for 1 hr, L363 antibody conjugated with biotin was added for 30 min at RT, followed by incubation with streptavidin-HRP for 30 min at RT and detection with an ELSIA reader. KD values of the binary complex were calculated from the linear regression of the Scatchard transformation of the L363 antibody binding curve.

Expansion of Human iNKT Cells

Human naïve Vα24⁺ iNKT cells were cultured with autologous immature CD14⁺ DCs pulsed with the indicated glycolipid at 100 ng/ml or DMSO on day 2 for 18 h. On day 3, the suspension cells were transferred to a new dish, cultured in the presence of 50 U/ml IL-2 (R & D Systems), and replenished with fresh medium every 3 days. The percentage of Vα24⁺/Vβ11⁺ cells was determined by flow cytometry on day 9. The total cell number after expansion was calculated with the Guava ViaCount reagent (Millipore, USA) and detected by the Guava system with CytoSoft™ software containing the ViaCount module (Millipore, USA).

Binding Avidity of Various CD1d-Loaded Glycolipids to Vα14⁺ iNKT Cells

Briefly, murine CD1d:Ig dimer (BD Biosciences PharMingen, San Diego, Calif.) was loaded with glycolipids at a molar ratio of 1:10 or vehicle for overnight at 37° C. Murine 1.2 Vα14⁺ iNKT cells were incubated with various doses of dimer-glycolipid complex in buffer containing azide (0.05%) for 30 min at 4° C. These cells were then stained with anti-mouse IgG1-PE mAb (A85-1) for another 30 min at 4° C., followed by washing, fixation with 4% paraformaldehyde (PFA), and the bound mCD1d dimer complexes were detected by flow cytometry. The binding curve and linear fit of the Scatchard transformation were plotted by Graphpad Prism software.

Binding Avidity of CD1d-Loaded Glycolipids with Vα24⁺ iNKT Cells

Binding avidity of human CD1d-glycolipid complexes to Vα24⁺ iNKT cells expanded by 7DW8-5 at 100 ng/ml was determined as described previously.¹⁹

Isolation and Generation of Human Vα24⁺ iNKT Cell Lines and Immature Monocyte-Derived Dendritic Cells

Vα24⁺ iNKT cells and CD14⁺ cells were isolated from peripheral blood cells as described previously.¹⁹ Immature DCs were generated from the CD14⁺ cells after 2-day incubation in the presence of 300 U/ml GM-CSF (R & D Systems) and 100 U/ml IL-4 (R& D Systems).

Vα24⁺ iNKT cell lines expanded with 7DW8-5 or C1 were generated as follows. After irradiation with 2,000 rad, the immature DCs were cocultured with syngenic Vα24⁺ iNKT cells in the presence of 7DW8-5 or C1 at 100 ng/ml for 1 day. The cells were expanded in the presence of 50 U/ml IL-2 for 10-14 days after lipid removal. The same procedures were repeated once for further stimulation and expansion of iNKT cells. The 7DW8-5 or C1-expanded iNKT cell line was shown to express Vα24 T cell antigen receptor (>95% purity).

mCD1d Vs. hCD1d Swapping Assay

Murine DN3A4-1.2 Vα14⁺ iNKT hybridoma cells or C1-expanded Vα24⁺ iNKT cells were pulsed with the indicated glycolipid antigen presented either by mCD1d (A20-CD1d cells) or hCD1d (HeLa-CD1d cells) at 1, 0.1, and 0.01 μg/ml. After 18 hr, the supernatants were harvested for the measurement of cytokine secretion(s). IL-2 released from Vα14⁺ iNKT cells was determined by ELISA assay. IFN-γ, IL-4 and IL-2 secreted from Vα24⁺ iNKT cells were detected using Beadlyte® Human Cytokine kit (Millipore, N.Y., USA) and Luminex® 200™ reading system.

Computer Modeling and Simulation

The crystal structures of both human and mouse CD1d (hCD1d and mCD1d) presenting α-GalCer to their respective iNKT TCRs were retrieved from the RCSB Protein Data Bank (www.rcsb.org; PDB coded 3HUJ, 3QUX, 3QUY, 3QUZ, and 3HE6). These crystal structures were superimposed by referencing to the backbone atoms of 3QUX. The two α-GalCer ternary structures obtained from 3HE6 and 3HUJ were used to create the other ternary complexes composed of different GSLs. The ternary structure containing C34 was derived from that containing C1 by modifying the acyl chain on Meastro (Schrödinger LLC, USA). The ternary structures bearing C1-Glc and C34-Glc were created by a inverting the O4 chirality of C1 and C34, respectively. The modeling for the remaining new ternary complexes were built using these GSLs and CD1d-iNKT TCR structures from 3QUX and 3HUJ for mice and humans, respectively. All structures were processed using Protein Preparation wizard (Schrödinger LLC, USA) and the lipid tails were further refined to minimize the steric collision using MacroModel's conformation search and energy minimization with the default methods and OPLS2005 force field in a solvent of water. The binding modes of GSLs to iNKT TCRs were recomputed by Autodock4.2 using a semi-empirical free energy force field to evaluate conformations during simulations. The estimated free energy of binding in solvent was computed by the equation built in the Autodock4.2: ΔG=ΔV ^(L)(bound-undound)+ΔV ^(P)(bound-undound)+ΔV ^(PL)(bound-unbound+ΔS _(conf)).

where L refers to the “ligand”; P refers to the “protein”; V refers to the pair-wise energetic terms including evaluations for dispersion/repulsion, hydrogen bonding, and electrostatics; ΔS_(conf) is an estimate of the conformational entropy lost upon binding. All required input files for running Autodock4 were prepared on MGLTools. A grid box of 60×60×60 Å³ and various atom-typed energy maps were generated. In each molecular docking run, all hydroxyl groups were set to free rotation and the two lipid tails were assigned to their prior refined poses. The Lamarckian genetic algorithm (maximum number of 5.0×10⁷ energy evaluations and 27,000 generations and a mutation rate of 0.02 with a crossover rate of 0.8) was employed for search. The results were visualized in MGLTools and the contribution of hydrogen bonding to individual residue was obtained by the built in function. Graphic representation was finished on Maestro.

Results

Glycosphingolipids (GSLs) with αGlc are Stronger Immune Modulators than Those with αGal in Humans but Weaker in Mice

Previously, 0.1 μg/mouse of 7DW8-5 was sufficient for immune stimulation,¹⁹ but higher dosage (1 μg/mouse) was required for the glucose analog 7DW8-5-Glc to induce immune responses (FIG. 6). Thus, the biological activities of newly synthesized glycolipids were tested in B6 mice 2 and 18 hr after i.v. injection of glycolipids at 1 μg/mouse. As shown in FIG. 2 and FIG. 7, the mannose analog 7DW8-5-Man failed to induce any cytokines/chemokines. As compared to GSLs with αGlc, GSLs with αGal induced higher levels of cytokines and chemokines, including IFN-γ, IL-2, IL-4, IL-6, GM-CSF, TNFα and IP-10. A similar trend was noted for αGalCer and C34 analogs with different glycosyl groups (FIGS. 2A, 2B and FIG. 7).

Although C1-Glc and C34-Glc triggered both cytokines and chemokines, 7DW8-5-Glc induced very low levels of Th1 and Th2 cytokines but relatively high levels of KC, MCP-1, IP-10 and MIG chemokines. To probe the possibility that other immune cells than iNKT cells might contribute to the chemokine induction by 7DW8-5-Glc, Jα18 KO mice which harbored no iNKT cells were injected with 7DW8-5-Glc or 7DW8-5 at 1 μg/mouse.²⁵ Mouse sera collected 2 and 18 hr after injection showed no induction of cytokines by either 7DW8-5 or 7DW8-5-Glc (FIGS. 2A, 2B and FIG. 7). Surprisingly, 7DW8-5-Glc but not 7DW8-5 triggered the secretion of several chemokines including KC, MCP-1, IP-10 and MIG in Jα18 KO mice. These findings suggested that immune cells other than iNKT cells in Jα18 KO mice must have contributed to the production of chemokines in WT mice and Jα18 KO mice treated with 7DW8-5-Glc.

Next, we analyzed the expansion/activation of immune cells in WT mice 3 days after glycolipid stimulation. The numbers of total T cells, CD4⁺ T and CD8⁺ T cells were higher in mice treated by GSLs with αGal head than those treated by GSLs with αGlc (FIGS. 2C, 8E and 8F). This was in line with the observation that more cytokines/chemokines were induced by GSLs with αGal than GSLs with αGlc in mice (FIGS. 2A, 2B and 7). Further comparison of immunostimulatory activities among GSLs with αGlc revealed that both C1-Glc and C34-Glc were better than 7DW8-5-Glc in the induction of cytokines/chemokines (FIGS. 2A, 2B and 7) and the expansion/activation of DCs (FIG. 8B-8D). C34-Glc activated ˜2 fold more CD80⁺ or CD86⁺ DCs than 7DW8-5-Glc (FIGS. 8C and 8D) although they induced similar numbers of total splenocytes and DCs (FIGS. 8A and 8B). As compared to 7DW8-5-Glc, C1-Glc not only expanded ˜1.3 fold more splenocytes and DCs (FIGS. 8A and 8B) but also activated ˜3.5 fold more CD80⁺ DCs as well as ˜3 fold more CD86⁺ DCs (FIGS. 8C and 8D). The increased expansion/activation of DCs may contribute to the stronger immunogenicity triggered by C1-Glc and C34-Glc as compared to 7DW8-5-Glc in vivo. In contrast, 7DW8-5-Man did not expand any types of immune cells (FIGS. 2C and 8), consistent with the lack of induction of cytokines/chemokines (FIGS. 2A, 2B and 7).

Unexpectedly, we also observed that 7DW8-5-Glc induced chemokines in Jα18 KO mice (FIG. 7). FACS analyses of Jα18 KO mouse splenocytes 3 days after i.v. injection of 7DW8-5-Glc or 7DW8-5 revealed that CD11c^(hi) monocyte-derived DCs were significantly expanded and activated by 7DW8-5-Glc but not 7DW8-5 (FIG. 9B-9D). No significant differences in the total splenocytes, CD4⁺ T and CD8⁺ T cells were noted after stimulation with either 7DW8-5 or 7DW8-5-Glc (FIGS. 9A, 9E and 9F). These findings indicated that monocytes might be responsible for the induction of chemokines such as KC, MCP-1, IP-10 and MIG in Jα18 KO mice treated with 7DW8-5-Glc.

As described above, glycolipid analogs with αGal were stronger immune modulators than those with αGlc in mice, especially for the comparison between 7DW8-5 and 7DW8-5-Glc. To investigate if similar trends also applied to human iNKT cells, Vα24⁺ iNKT cells isolated from the peripheral blood were incubated with immature DCs pulsed with the indicated glycolipid at 100 ng/ml on day 2. After antigen removal on day 3, human iNKT cells were cultured in the presence of IL-2. The number of expanded iNKT cells was counted using the Guava ViaCount reagent on day 9. Surprisingly, 7DW8-5-Glc was significantly (p=0.0009) better than 7DW8-5 in expanding human iNKT cells in vitro (FIG. 2D). Taken together, these findings suggested that the bioactivities of GSLs with αGal were more potent in mice but less in humans as compared to GSLs with αGlc.

Binary Interaction Between mCD1d and Glycolipids

To understand the basis for the differences in the immune modulating activities of 7DW8-5 and 7DW8-5-Glc, we measured the binding strength of the binary interaction between mCD1d and specific glycolipid using L363 mAb which could bind to mCD1d complexed with glycolipids.²⁶ Various concentrations of mCD1d^(di)-glycolipid complexes at fixed ratio were incubated with saturated amounts of L363-biotin antibody, followed by streptavidin-HRP detection and ELISA measurement (FIG. 10A). The dissociation constant (KD) between L363 and the indicated mCD1d^(di)-glycolipid complexes was calculated from the linear regression of the Scatchard transformation of the plot (FIG. 10A) using GraphPad Prism software. L363 was found to recognize mCD1d^(di)-7DW8-5-Glc complex with similar binding strength as with mCD1d^(di)-7DW8-5 complex (FIG. 10B). Next, we determined the KD of the binary complex by incubating different concentrations of glycolipids with fixed amounts of mCD1d dimer and L363-biotin antibody, followed by streptavidin-HRP detection and ELISA measurement (FIG. 10C). The KD was calculated from the Scatchard transformation of the binding curve drawn from the L363 detection readout (FIG. 10D). Not surprisingly, 7DW8-5-Glc having identical lipid tails as 7DW8-5 bound to mCD1d dimer with similar strength, but their binding avidities were ˜20 fold greater than αGalCer. This indicated that the strength of the binary interaction could not account for the differential immune activating capacities between 7DW8-5 and 7DW8-5-Glc.

Ternary Interaction Between CD1d-GSL Complexes and iNKT Cells

Next, we measured the ternary interaction between CD1d-glycolipid complex and the iNKT TCR in mice and humans. Different concentrations of mCD1d^(di)-glycolipid and hCD1d^(di)-glycolipid complexes were incubated with fixed amounts of DN3A4-1.2 murine iNKT hybridoma cells and human Vα24⁺/Vβ11⁺ iNKT cells, respectively. The level of bound complexes at the indicated concentration was detected by anti-mIgG1 secondary antibody and analyzed by flow cytometry (FIGS. 3A and 3B). The KD of the ternary complex was calculated from the Scatchard transformation of the plots in FIGS. 3A and 3B using GraphPad Prism software. As shown in FIG. 3C, mCD1d-7DW8-5 complex displayed ˜10-fold stronger interaction with iNKT TCR than mCD1d-7DW8-5-Glc complex. This was consistent with the observation that higher percentages of C1-pulsed splenocytes were stained by the mCD1d-7DW8-5 complex (36.2±5.0%) than mCD1d-7DW8-5-Glc complex (17.1±0.8%) (FIG. 11). When complexed with mCD1d, both C1 (KD: 1.240±0.003 nM) and C34 (KD: 0.735±0.010 nM) exhibited stronger ternary interactions toward iNKT TCR than C1-Glc (KD: 5.137±0.110 nM) and C34-Glc (KD: 7.960±1.269 nM), respectively (FIG. 3C).

In humans, GSLs with αGlc (KD of C1-Glc: 8.550±0.617; C34-Glc: 0.378±0.019; 7DW8-5-Glc: 0.481±0.008 nM) exhibited stronger ternary interactions toward Vα24⁺/Vβ11⁺ iNKT TCR than GSLs with αGal (KD of C1: 16.410±4.200; C34: 0.498±0.005; 7DW8-5: 0.777±0.022 nM) in complex with hCD1d (FIG. 3D). Thus, irrespective of the types of lipid tails, GSLs with αGal exhibited stronger ternary interaction with mouse iNKT TCR but weaker ternary interaction with human iNKT TCR than GSLs with αGlc (FIGS. 3C and 3D). This may account for the observation that GSLs with αGal triggered higher levels of cytokines/chemokines and greater expansions of immune cells in mice (FIGS. 2A-2C, 7 and 8) while less iNKT cell expansion in humans (FIG. 2D) Taken together, the ternary interaction among iNKT TCR, CD1d and GSL seems to be more relevant for the bioactivities of glycolipids than the binary interaction between CD1d and GSL.

Effects of Swapping Human Vs. Mouse CD1d Molecules Against iNKT Cells

To explain the species-specific responses, we examined the effects of swapping human vs. mouse CD1d molecules against human vs. murine iNKT cells on the stimulatory activities of GSLs with different glycosyl groups. Murine iNKT hybridoma cells (FIG. 4A) or C1-expanded human Vα24⁺ iNKT cells (FIG. 4B) were pulsed with the indicated glycolipid presented by either mCD1d (A20-CD1d) or hCD1 d (HeLa-CD1d). The supernatants were harvested 24 hr later to measure the cytokine secretions. Whether presented by mCD1d or hCD1d, GSLs with αGal induced more IL-2 secretion than GSLs with αGlc from murine iNKT cells (FIG. 4A). This was consistent with the in vivo findings that GSLs with αGal were more potent than GSLs with αGlc to induce serum cytokine secretion (FIGS. 2 and 7). In contrast, when presented by either mCD1d or hCD1d, GSLs with αGlc triggered more IL-2 secretion than GSLs with αGal from human iNKT cells (FIG. 4B). Similar trends were also observed on IFN-γ and IL-4 secretions from human iNKT cells (FIG. 12A and FIG. 12B). The species-specific stimulatory activities of GSLs with different glycosyl groups were dictated by the murine vs. human iNKT TCR, rather than CD1d. In comparison, 7DW8-5-Man could not stimulate mouse and human iNKT cells to secret any cytokines regardless of its presentation by mCD1d or hCD1d. Notably, all GSLs with αGlc triggered significantly more Th1-skewed responses than C1 based on the ratio of IFN-γ over IL-4 (FIG. 12C). Besides, irrespective of lipid tails, GSLs with αGlc seemed more Th1-biased than GSLs with αGal in humans (FIG. 12C). These findings indicated that modification at the 4′-OH of the glycosyl group could selectively induce the responses of human iNKT cells toward Th1 direction.

Structural Modeling of the Ternary Complex of CD1d-GSL-iNKT TCR

To further explain differential binding avidities of the ternary complex in mice and men, computer modeling was performed based on the x-ray structures of murine and human CD1d-αGalCer-iNKT TCR complexes, respectively (PDB access code 3HUJ, 3QUX, 3QUY, 3QUZ, and 3HE6).²⁷⁻²⁹

(1) Interactions of the Sugar Head Groups

As shown in FIGS. 3A and 3B, the GSL with Man could not bind to the mouse and human iNKT cells when complexed with CD1d. A vertical 2′OH in mannose created a steric hindrance against iNKT TCR (Ser30 in men and Asn30 in mice) and lost two hydrogen bonds originally formed by the 2′OH of galactose toward the iNKT TCR (Gly96 and Asp151 in men as well as Gly96 and Asp153 in mice). As for GSLs with Gal, the binding of C1 to CD1d and iNKT TCR for mice and humans was shown in FIGS. 5A and 5B, respectively. Formations of hydrogen bond (H-bond) interactions were observed in most conserved residues, including human Asp80 (mouse Asp80), human Thr154 (mouse Thr156), human Asp151 (mouse Asp 153) of CD1d and human Gly96 (mouse Gly96) of iNKT TCR. On the other hand, the H-bond interactions of the 3′OH/4′OH of C1 with human and mouse iNKT TCR were quite different. The residue Asn30 of mouse iNKT TCR was crucial for binding to the 3′- and 4′-OHs of C1. The free energy contribution of Asn30 was estimated to be −2.27˜−3.38 Kcal/mol using MGLTools. In comparison, Ser30 of human iNKT TCR was more distant from the 4′-OH of C1, resulting in a weaker H-bond interaction with the 3′-OH only, while a H-bond could be formed between 4′-OH of C1 and the backbone C═O group of Phe29 (FIG. 5B). The free energy contribution of Ser30 with the 3′-OH and Phe29 with the 4′-OH of C1 was computed to be about −1.23˜−1.63 Kcal/mol. Thus, a change from axial (Gal) to equatorial (Glc) direction of 4′ OH would lose the H-bond interaction with mouse Asn30 and human Phe29 of iNKT TCRs. As compared to C1 and C34, respectively, C1-Glc and C34-Glc lacked the H-bond interaction with murine Asn30, leading to a decreased free energy (−0.7˜−0.9 Kcal/mol calculated by MGLTools). This was in line with the drops in the murine ternary interaction in the KD measurement (FIG. 3C) when galactose was changed to the glucose head. On the contrary, human ternary interactions were greater for GSLs with glucose (FIG. 3D). Based on the computer modeling, we found that the equatorial 4′-OH of glucose could compensate for the loss of Phe29 interaction (−0.4 Kcal/mol) by a stronger interaction (˜−1.84 Kcal/mol) with a crystal water, which was trapped by human iNKT TCR-Phe51 and hCD1d-Trp153 (FIG. 5C). Without the formation of hydrophobic space and the trapped water molecule in mice, the ternary interaction would be weaker for GSLs with Glc than those with Gal.

(2) Interactions of the Lipid Tails

The two aromatic rings at the acyl tail of C34 could form aromatic interactions with Phe70 and Trp63 of CD1d. Thus, the change of the acyl tail from C1 to C34 could increase the interaction (−1.8˜−2.4 Kcal/mol by modeling) with CD1d. In addition, the higher energy from aromatic interactions could drive the acyl chain of C34 or C34-Glc to a lower position (near Cys12) of the A′ channel within CD1d, leading to a subtle perturbation to the orientation of the head group (FIG. 5D). Therefore, without a congenial force between mouse iNKT TCR and the equatorial 4′-OH of the glucose head, the binding of mCD1d-C34-Glc to iNKT TCR was a little weaker than mCD1d-C1-Glc (FIG. 3C). This may explain why C34-Glc was less potent than C1-Glc while C34 was superior to C1 in mice.

(3) Computed Free Energy Using AUTODOCK4

The free energy of each GSL bound to human and mouse CD1d-iNKT TCRs was computed in triplicate. In each round, the GSLs were docked to the human and mouse CD1d-C1-iNKT TCRs and the topmost ranked free energies were selected. As shown in FIG. 5E, the computed free energy in general correlated with the trends of the KD values measured for mice (FIG. 3C) and humans (FIG. 3D).

A variety of means can be used to formulate the compositions of the invention. Techniques for formulation and administration may be found in “Remington: The Science and Practice of Pharmacy,” Twentieth Edition, Lippincott Williams & Wilkins, Philadelphia, Pa. (1995). For human or animal administration, preparations should meet sterility, pyrogenicity, and general safety and purity standards comparable to those required by the FDA. Administration of the pharmaceutical formulation can be performed in a variety of ways, as described herein.

Cytokine Induction and Ternary Interactions Among GSLs, CD1d and iNKT TCR

As compared to αGalCer, αGlcCer has been reported to be less stimulatory on the murine iNKT cell proliferation but appeared more potent to stimulate human iNKT cell proliferation.^(5,22) In our studies, the differential activities between αGalCer and αGlcCer in mice and humans were also observed on the cytokine induction and ternary interaction among GSLs, CD1d and iNKT TCR. Furthermore, phenyl GSLs bearing αGal or αGlc head showed similar species-specific activities. Thus, irrespective of lipid tails, GSLs with αGal were better than GSLs with αGlc in mice but worse in men. This indicated that the bioactivity of glycolipids in mice cannot be translated to that in humans despite the highly homologous sequences of CD1d and iNKT TCR between mice and humans.³⁰

The species-specific responses were most likely attributed to the differences in iNKT TCR between mice and men, as demonstrated by mCD1d vs. hCD1d swapping assay. GSLs with αGal, either presented by mCD1d or hCD1d, were more potent than GSLs with αGlc to stimulate murine iNKT cells but less stimulatory for human iNKT cells. According to the crystal structures of CD1d-αGalCer-iNKT TCR, the residues in contact with the 4′-OH of the galactose head in the CDR1α region of iNKT TCR were not conserved between mice (Asn30) and humans (Phe29).^(27,28) Our computer modeling revealed that the change of 4′-OH from the axial to equatorial direction could result in the loss of hydrogen bond between the 4′OH and iNKT TCR-Asn30 in mice. On the contrary, the equatorial 4′-OH of glucose could compensate for the loss of Phe29 interaction by a stronger interaction with a crystal water, which was trapped by human iNKT TCR-Phe51 and hCD1d-Trp153. Thus, the ternary interaction composed of GSLs with αGlc was stronger than GSLs with αGal in humans but weaker in mice. Taken together, the structural modeling of murine and human CD1d-GSL-iNKT TCR complexes provided a good explanation for species-specific biological activities, and the computed free energy changes correlated well with the trends of measured binding avidities of the ternary complex.

In contrast to our paired analogues with the same tail but different glycosyl groups, the species-specific immune responses were also seen in other cases with the same glycosyl group but different lipid tails.^(31,32) Similarly, it was the iNKT TCR, instead of CD1d, that shaped the preferential activities of two C-glycoside analogs between mice and men, which correlated well with the binding strengths of the ternary complex.³¹ For our glycolipids, ternary interaction was also more important than binary interaction in predicting the biological responses in mice and men. Both 7DW8-5 and 7DW8-5-Glc bound with mCD1d much stronger than C1, probably due to the increased contacts of the phenyl ring and the fluoride atom with the CD1d A′ pocket.³³ Even though the two glycolipids with the same lipid tails exhibited similar binding strengths toward CD1d, they showed different immune stimulatory potencies. 7DW8-5-Glc was better than 7DW8-5 in men but worse in mice, which had a good relationship with the binding avidities of ternary complexes. In addition to 7DW8-5 and 7DW8-5-Glc, the bioactivities of the other two paired analogues (C1 vs. C1-Glc and C34 vs. C34-Glc) also correlated well with the strengths of the ternary interaction in mice and men. That is, GSLs with αGal showed stronger ternary interaction and immune stimulatory activities than GSLs with αGlc in mice, but the trend was opposite in men. Hence, the measurement of the ternary interaction in vitro could be used to predict the immune-stimulatory potency of our new glycolipids in vivo.

Further comparison among GSLs with αGlc revealed that both C1-Glc and C34-Glc were better than 7DW8-5-Glc in cytokine induction in mice. However, the binding avidities of the murine ternary complex were comparable for C34-Glc and 7DW8-5-Glc. These findings suggested that factors other than KD may also modulate immune responses in vivo. In fact, both C1-Glc and C34-Glc activated more CD80⁺ or CD86⁺ DCs than 7DW8-5-Glc, which may contribute to the stronger bioactivities of C1-Glc and C34-Glc in mice. Taken together, several factors, including the strength of the ternary interaction and the expansion/activation of immune cells, could regulate immune stimulation in vivo.

In contrast to GSLs with αGal or αGlc, αManCer and 7DW8-5-Man failed to induce iNKT cell proliferation,^(5,22) cytokines/chemokines, and/or the expansion/activation of immune cells in both mice and humans. This may be attributed to the fact that neither murine nor human iNKT TCR could recognize the αMan head, as demonstrated by the lack of staining with CD1d-7DW8-5-Man dimer in iNKT cells. As compared to 7DW8-5-Man, 7DW8-5-Glc was able to induce Th1 and Th2 cytokines albeit at very low levels in mice. In comparison, large amounts of KC, MCP-1, IP-10 and MIG chemokines were triggered by 7DW8-5-Glc in WT and Jα18 KO mice, indicating that certain types of immune cells other than iNKT cells may contribute to these chemokine secretions. Indeed, monocytes were significantly expanded/activated in Jα18 KO mice by 7DW8-5-Glc. It had been reported that monocytes could produce these chemokines in response to stimulations,³⁴⁻³⁷ suggesting that monocytes may be responsible for chemokine secretions in 7DW8-5-Glc-treated mice. Nevertheless, we could not exclude that other possible sources existing in Jα18 KO mice may also play a role. Vα10 NKT cells could produce IFN-γ and IL-4 in response to αGalCer and αGlcCer in vitro,³⁸ but IFN-γ was not secreted in the sera of Jα18 KO mice treated with αGalCer.³⁹ We could not detect any cytokine productions from Jα18 KO mice treated with 7DW8-5 or 7DW8-5-Glc. These findings implied that Vα10 NKT cells contributed little to the chemokines triggered by 7DW8-5-Glc in mice.

However, most of the cytokines and chemokines, including IFN-γ, IL-2, IL-4, IL-6, GM-CSF and TNFα were not produced in Jα18 KO mice stimulated with either 7DW8-5 or 7DW8-5-Glc. Immune cells like CD4⁺ T and CD8⁺ T cells were not expanded in Jα18 KO mice either. Thus, iNKT cells remained to be the key player in the above-mentioned cytokine/chemokine induction and immune cell expansion by 7DW8-5 or 7DW8-5-Glc.

In summary, GSLs with αGlc bore stronger ternary interaction and triggered more Th1-biased immunity as compared to GSLs with αGal in humans. However, GSLs with αGlc were less stimulatory than GSLs with αGal in mice. The species-specific responses were attributed to the differential binding avidities of ternary complexes between species, reflecting the differences between murine and human iNKT TCR as supported by mCD1d vs. hCD1d swapping assay. This was in line with the prediction by the computer modeling based on the crystal structures of the CD1d-αGalCer-iNKT TCR complex in mice and men.²⁷⁻²⁹ In addition to the ternary interaction between CD1d-glycolipid complex and iNKT TCR, expanded/activated monocytes could also modulate immune responses in vivo, especially for GSLs with αGlc.

From our studies, the change of the 4′OH direction on the glycosyl group led to different bioactivities in mice and humans. This was consistent with the report that the aromatic group introduced to 4′ OH of the αGalCer head could affect iNKT cell cytokine production in mice, but their effects in humans were not investigated.⁴⁰ Alterations at the 6 position of the glycosyl group also showed variable effects on the biological responses.^(29,41) These findings together with our work provided a new direction for the future design and synthesis of new GSLs.

Throughout this application, various publications, patents and published patent applications are cited. The inventions of these publications, patents and published patent applications referenced in this application are hereby incorporated by reference in their entireties into the present invention. Citation herein of a publication, patent, or published patent application is not an admission the publication, patent, or published patent application is prior art.

All publications and patent applications cited in this specification are herein incorporated by reference as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of ordinary skill in the art in light of the teachings of this invention that certain changes and modifications may be made thereto without departing from the spirit or scope of the appended claim. 

We claim:
 1. An immune adjuvant compound having Formula (I):

or a pharmaceutically acceptable salt thereof; wherein: R¹ is —OH or halogen; R² is —OH; R³ is hydrogen; each instance of R⁴ and R⁵ is independently selected from the group consisting of hydrogen, halogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted aryl, optionally substituted heterocyclyl, optionally substituted heteroaryl, optionally substituted alkoxy, an optionally substituted amino group, or optionally substituted acyl; n is an integer of 5 to 15, inclusive; m is an integer of 1 to 20, inclusive.
 2. The compound of claim 1, wherein R¹ is —OH.
 3. The compound of claim 1, wherein R¹ is halogen.
 4. The compound of claim 1, wherein R⁴ is of Formula (II):

wherein: i is 0, 1, 2, 3, 4, or 5; R⁶ is independently selected from the group consisting of hydrogen, halogen, —CN, —NO₂, —N₃, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted aryl, optionally substituted heterocyclyl, optionally substituted heteroaryl, optionally substituted alkoxy, an optionally substituted amino group, or optionally substituted acyl.
 5. The compound of claim 4, wherein R⁶ is halogen.
 6. The compound of claim 4, wherein R⁶ is F.
 7. The compound of claim 1, wherein R⁴ is of Formula (III):

wherein: j is 0, 1, 2, 3, or 4; k is 0, 1, 2, 3, 4, or 5; each instance of R⁷ and R⁸ is independently selected from the group consisting of hydrogen, halogen, —CN, —NO₂, —N₃, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted aryl, optionally substituted heterocyclyl, optionally substituted heteroaryl, optionally substituted alkoxy, an optionally substituted amino group, or optionally substituted acyl.
 8. The compound of claim 7, wherein each instance of R⁷ and R⁸ is independently hydrogen or halogen.
 9. The compound of claim 7, wherein R⁷ is hydrogen; R⁸ is F; and k is 1, 2 or
 3. 10. The compound of claim 7, wherein R⁷ is F; R⁸ is hydrogen; and j is 1, 2 or
 3. 11. The compound of claim 7, wherein R⁷ and R⁸ both are F; k is 1, 2 or 3; and j is 1, 2 or
 3. 12. The compound of claim 1, wherein the compound is selected from one of the following:


13. A pharmaceutical composition comprising: (i) a compound according to any of claims 1 or 12 in an amount sufficient to stimulate an immune response when co-administered with an antigen to a human subject, and (ii) a pharmaceutically acceptable excipient.
 14. The pharmaceutical composition of claim 13, wherein the composition is a vaccine adjuvant.
 15. The pharmaceutical composition of claim 13, wherein the composition is an anti-cancer therapeutic.
 16. The pharmaceutical composition of claim 13, wherein R⁴ in the compound is selected from substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl, and wherein the compound is capable of increasing Th1 cytokines in humans with minimum accompanying increase in Th2 cytokines.
 17. A method for stimulating an immune response in a human subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of an immune adjuvant composition in a pharmaceutically acceptable carrier, wherein the composition comprises a compound according to any of claim 1 or
 12. 18. A method for augmenting the immune response by an antigen in a subject, the method comprising administering to the subject an effective amount of a vaccine comprising one or more antigens and an immunogenically effective amount of an adjuvant composition of claim
 13. 19. The method of claim 18, wherein the one or more antigens are selected from the group consisting of bacterial antigen, viral antigen, fungal antigen, protozoal antigen, prion antigen, neoantigen, tumor antigen and self-antigen.
 20. The method of claim 18, where the vaccine is selected from the group consisting of a nucleic acid, protein, peptide, glycoprotein, carbohydrate, fusion protein, lipid, glycolipid, carbohydrate-protein conjugate; cells or extracts thereof; dead or attenuated cells, or extracts thereof; tumor cells or extracts thereof; viral particles; allergens or mixtures thereof.
 21. The method of claim 18 wherein the antigen administered is a tumor antigen.
 22. The method of claim 18, wherein said the amount of antigen is administered in the range of 0.1 μm-100 mg per kg of body weight.
 23. The method of claim 18, wherein said amount of the adjuvant is in the range of 10-100 μm per kg of body weight.
 24. The method of claim 18 wherein the composition coadministered is a coformulated pharmaceutically acceptable composition comprising the GSLs of Formula I and a pharmaceutically acceptable carrier.
 25. A method for elevating invariant Natural Killer T (iNKT) cells production in a human subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of a pharmaceutical composition, wherein the composition comprises a compound according to claim
 1. 26. A method for stimulating cytokine and/or chemokine production in a human subject in need thereof, the method comprising: administering to the subject a therapeutically effective amount of a pharmaceutical composition, wherein the composition comprises a compound according to claim 1 in an amount sufficient to increase cytokine/chemokine production.
 27. The method of claim 26, wherein the cytokine production is sufficient to transactivate downstream immune cells.
 28. The method of claim 27, wherein the downstream immune cells comprise one or more of dendritic cells (DC), natural killer cells (NK), B cells, CD4⁺T and CD8⁺T cells.
 29. The method of claim 26, wherein the cytokines comprise Th1 cytokines.
 30. The method of claim 29, wherein the cytokines are selected from: interferon-gamma (IFN-γ), GM-CSF, TNFα, interleukin 2, interleukin 12 and interleukin10.
 31. The method of claim 26, wherein the chemokines are selected from: RANTES, MIP-1α, KC, MCP-1, IP-10 and MIG.
 32. A method for augmenting an immunogenicity of an antigen in a subject in need thereof, comprising co-administering said antigen with an adjuvant composition comprising a GS Ls compound of the genera Formula (I):

or a pharmaceutically acceptable salt thereof; wherein: R¹ is —OH or halogen; R² is —OH; R³ is hydrogen; each instance of R⁴ and R⁵ is independently selected from the group consisting of hydrogen, halogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted aryl, optionally substituted heterocyclyl, optionally substituted heteroaryl, optionally substituted alkoxy, an optionally substituted amino group, or optionally substituted acyl; n is an integer of 5 to 15, inclusive; m is an integer of 1 to 20, inclusive.
 33. The method of claim 32, wherein the adjuvant composition is a vaccine adjuvant.
 34. The method of claim 32, wherein the adjuvant composition is administered in amount capable of elevating invariant Natural Killer T (iNKT) cells in humans.
 35. The method of claim 34, wherein administration of the adjuvant composition increases cytokine and/or chemokine production in humans.
 36. The method of claim 35, wherein the cytokine production is sufficient to transactivate downstream immune cells.
 37. The method of claim 36, wherein the downstream immune cells comprise one or more of dendritic cells (DC), natural killer cells (NK), B cells, CD4⁺T and CD8⁺T cells.
 38. The method of claim 37, wherein the cytokines comprise Th1 cytokines.
 39. The method of claim 38, wherein the Th1 cytokines is selected from at least one of the group comprising: interferon-gamma (IFN-γ), GM-CSF, TNFα, interleukin 2, interleukin 12 and interleukin10.
 40. The method of claim 35, wherein the chemokine is selected from at least one of the group comprising RANTES, MIP-1α, KC, MCP-1, IP-10 and MIG.
 41. The method of claim 32, wherein administration of the composition has an anti-cancer effect.
 42. The method of claim 41, wherein the cancer is selected from the group consisting of lung cancer, breast cancer, hepatoma, leukemia, solid tumor and carcinoma.
 43. The method of claim 32, wherein R⁴ in the compound of Formula I is selected from substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl, and wherein increase in Th1 cytokines in humans exceeds any increase in Th2 cytokines. 